springboot核心

springboot核心

本文源文件来自尚硅谷雷丰阳老师,将其使用的springboot 1.x替换成了springboot 2.x并在一些部分作出了一些补充,包括配置、日志、web、docker、数据访问。

一、Spring Boot 入门

1、Spring Boot 简介

简化Spring应用开发的一个框架;

整个Spring技术栈的一个大整合;

J2EE开发的一站式解决方案;

2、微服务

2014,martin fowler

微服务:架构风格(服务微化)

一个应用应该是一组小型服务;可以通过HTTP的方式进行互通;

单体应用:ALL IN ONE

微服务:每一个功能元素最终都是一个可独立替换和独立升级的软件单元;

详细参照微服务文档

3、环境准备

环境约束

–jdk1.8:Spring Boot 推荐jdk1.7及以上;java version “1.8.0_112”

–maven3.x:maven 3.3以上版本;Apache Maven 3.3.9

–SpringBoot 2.2.6.RELEASE:2.2.6

1、MAVEN设置;

给maven 的settings.xml配置文件的profiles标签添加

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<profile>
<id>jdk-1.8</id>
<activation>
<activeByDefault>true</activeByDefault>
<jdk>1.8</jdk>
</activation>
<properties>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
<maven.compiler.compilerVersion>1.8</maven.compiler.compilerVersion>
</properties>
</profile>

2、IDEA设置

整合maven进来;

idea设置

images/

4、Spring Boot HelloWorld

一个功能:

浏览器发送hello请求,服务器接受请求并处理,响应Hello World字符串;

1、创建一个maven工程;(jar)

2、导入spring boot相关的依赖

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<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.9.RELEASE</version>
</parent>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
</dependencies>

3、编写一个主程序;启动Spring Boot应用

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/**
* @SpringBootApplication 来标注一个主程序类,说明这是一个Spring Boot应用
*/
@SpringBootApplication
public class HelloWorldMainApplication {

public static void main(String[] args) {

// Spring应用启动起来
SpringApplication.run(HelloWorldMainApplication.class,args);
}
}

4、编写相关的Controller、Service

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@Controller
public class HelloController {

@ResponseBody
@RequestMapping("/hello")
public String hello(){
return "Hello World!";
}
}

5、运行主程序测试

6、简化部署

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<!-- 这个插件,可以将应用打包成一个可执行的jar包;-->
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>

将这个应用打成jar包,直接使用java -jar的命令进行执行;

5、Hello World探究

1、POM文件

1、父项目

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<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.9.RELEASE</version>
</parent>

他的父项目是
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-dependencies</artifactId>
<version>1.5.9.RELEASE</version>
<relativePath>../../spring-boot-dependencies</relativePath>
</parent>
他来真正管理Spring Boot应用里面的所有依赖版本;

Spring Boot的版本仲裁中心;

以后我们导入依赖默认是不需要写版本;(没有在dependencies里面管理的依赖自然需要声明版本号)

2、启动器

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<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>

spring-boot-starter-==web==:

​ spring-boot-starter:spring-boot场景启动器;帮我们导入了web模块正常运行所依赖的组件;

Spring Boot将所有的功能场景都抽取出来,做成一个个的starters(启动器),只需要在项目里面引入这些starter相关场景的所有依赖都会导入进来。要用什么功能就导入什么场景的启动器

2、主程序类,主入口类

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/**
* @SpringBootApplication 来标注一个主程序类,说明这是一个Spring Boot应用
*/
@SpringBootApplication
public class HelloWorldMainApplication {

public static void main(String[] args) {

// Spring应用启动起来
SpringApplication.run(HelloWorldMainApplication.class,args);
}
}

@SpringBootApplication: Spring Boot应用标注在某个类上说明这个类是SpringBoot的主配置类,SpringBoot就应该运行这个类的main方法来启动SpringBoot应用;

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@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Inherited
@SpringBootConfiguration
@EnableAutoConfiguration
@ComponentScan(excludeFilters = {
@Filter(type = FilterType.CUSTOM, classes = TypeExcludeFilter.class),
@Filter(type = FilterType.CUSTOM, classes = AutoConfigurationExcludeFilter.class) })
public @interface SpringBootApplication {

@SpringBootConfiguration:Spring Boot的配置类;

​ 标注在某个类上,表示这是一个Spring Boot的配置类;

​ @Configuration:配置类上来标注这个注解;

​ 配置类 —– 配置文件;配置类也是容器中的一个组件;@Component

@EnableAutoConfiguration:开启自动配置功能;

​ 以前我们需要配置的东西,Spring Boot帮我们自动配置;@EnableAutoConfiguration告诉SpringBoot开启自动配置功能;这样自动配置才能生效;

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@AutoConfigurationPackage
@Import(EnableAutoConfigurationImportSelector.class)
public @interface EnableAutoConfiguration {

​ @AutoConfigurationPackage:自动配置包

​ @Import(AutoConfigurationPackages.Registrar.class):

​ Spring的底层注解@Import,给容器中导入一个组件;导入的组件由AutoConfigurationPackages.Registrar.class;

==将主配置类(@SpringBootApplication标注的类)的所在包及下面所有子包里面的所有组件扫描到Spring容器;==

​ @Import(EnableAutoConfigurationImportSelector.class);

​ 给容器中导入组件?

EnableAutoConfigurationImportSelector:导入哪些组件的选择器;

​ 将所有需要导入的组件以全类名的方式返回;这些组件就会被添加到容器中;

​ 会给容器中导入非常多的自动配置类(xxxAutoConfiguration);就是给容器中导入这个场景需要的所有组件,并配置好这些组件; 自动配置类

有了自动配置类,免去了我们手动编写配置注入功能组件等的工作;

​ SpringFactoriesLoader.loadFactoryNames(EnableAutoConfiguration.class,classLoader);

==Spring Boot在启动的时候从类路径下的META-INF/spring.factories中获取EnableAutoConfiguration指定的值,将这些值作为自动配置类导入到容器中,自动配置类就生效,帮我们进行自动配置工作;==以前我们需要自己配置的东西,自动配置类都帮我们;

J2EE的整体整合解决方案和自动配置都在spring-boot-autoconfigure-1.5.9.RELEASE.jar;

6、使用Spring Initializer快速创建Spring Boot项目

1、IDEA:使用 Spring Initializer快速创建项目

IDE都支持使用Spring的项目创建向导快速创建一个Spring Boot项目;

选择我们需要的模块;向导会联网创建Spring Boot项目;

默认生成的Spring Boot项目;

  • 主程序已经生成好了,我们只需要我们自己的逻辑
  • resources文件夹中目录结构
    • static:保存所有的静态资源; js css images;
    • templates:保存所有的模板页面;(Spring Boot默认jar包使用嵌入式的Tomcat,默认不支持JSP页面);可以使用模板引擎(freemarker、thymeleaf);
    • application.properties:Spring Boot应用的配置文件;可以修改一些默认设置;

2、STS使用 Spring Starter Project快速创建项目


二、配置文件

1、配置文件

SpringBoot使用一个全局的配置文件,配置文件名是固定的;

•application.properties

•application.yml

配置文件的作用:修改SpringBoot自动配置的默认值;SpringBoot在底层都给我们自动配置好;

YAML(YAML Ain’t Markup Language)

​ YAML A Markup Language:是一个标记语言

​ YAML isn’t Markup Language:不是一个标记语言;

标记语言:

​ 以前的配置文件;大多都使用的是 xxxx.xml文件;

​ YAML:以数据为中心,比json、xml等更适合做配置文件;

​ YAML:配置例子

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server:
port: 8081

​ XML:

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<server>
<port>8081</port>
</server>

2、YAML语法:

1、基本语法

k:(空格)v:表示一对键值对(空格必须有);

空格的缩进来控制层级关系;只要是左对齐的一列数据,都是同一个层级的

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server:
port: 8081
path: /hello

属性和值也是大小写敏感;

2、值的写法

字面量:普通的值(数字,字符串,布尔)

​ k: v:字面直接来写;

​ 字符串默认不用加上单引号或者双引号;

​ “”:双引号;不会转义字符串里面的特殊字符;特殊字符会作为本身想表示的意思

​ name: “zhangsan \n lisi”:输出;zhangsan 换行 lisi

​ ‘’:单引号;会转义特殊字符,特殊字符最终只是一个普通的字符串数据

​ name: ‘zhangsan \n lisi’:输出;zhangsan \n lisi

对象、Map(属性和值)(键值对):

​ k: v:在下一行来写对象的属性和值的关系;注意缩进

​ 对象还是k: v的方式

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friends:
lastName: zhangsan
age: 20

行内写法:

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friends: {lastName: zhangsan,age: 18}

数组(List、Set):

用- 值表示数组中的一个元素

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pets:
- cat
- dog
- pig

行内写法

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pets: [cat,dog,pig]

3、配置文件值注入

在进行配置文件注入时,会同时加载application.properties和yml,不过properties的优先级更高,properties中没有配置的内容会使用yml的配置。

yml配置文件

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person:
lastName: hello
age: 18
boss: false
birth: 2017/12/12
maps: {k1: v1,k2: 12}
lists:
- lisi
- zhaoliu
dog:
name: 小狗
age: 12

properties配置文件

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person.last_name=张三
person.age=18
person.boss=true
person.birth=2010/01/01
person.maps.k1=mmm
person.maps.v1=aaa
person.maps.k2=dog
person.maps.v2.dog.name=xiaobei
person.maps.v2.dog.age=3
person.lists={abc,def,ghi}
person.dog.name=wangcai
person.dog.age=4

javaBean:

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/**
* 将配置文件中配置的每一个属性的值,映射到这个组件中
* @ConfigurationProperties:告诉SpringBoot将本类中的所有属性和配置文件中相关的配置进行绑定;
* prefix = "person":配置文件中哪个下面的所有属性进行一一映射
*
* 只有这个组件是容器中的组件,才能容器提供的@ConfigurationProperties功能;
*
*/
@Component
@ConfigurationProperties(prefix = "person")
public class Person {

private String lastName;
private Integer age;
private Boolean boss;
private Date birth;

private Map<String,Object> maps;
private List<Object> lists;
private Dog dog;

我们可以导入配置文件处理器,以后编写配置就有提示了

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<!--导入配置文件处理器,配置文件进行绑定就会有提示-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-configuration-processor</artifactId>
<optional>true</optional>
</dependency>

1、properties配置文件在idea中默认utf-8可能会乱码

调整

idea配置乱码

2、@Value获取值和@ConfigurationProperties获取值比较

@ConfigurationProperties @Value
功能 批量注入配置文件中的属性 一个个指定
松散绑定(松散语法) 支持 不支持
SpEL 不支持 支持
JSR303数据校验 支持 不支持
复杂类型封装 支持 不支持
  • 松散绑定:属性匹配规则

    ​ 标准方式 person.firstName

    ​ 方式一 大写用- person.first-name

    ​ 方式二 大写用_ person.first_name

  • SpEL: #{表达式} 表达式内可以使用各类运算符

  • JSR303数据校验: 对属性的格式校验,校验时在类上要标注@Validated,对字段的校验常见的有@Email(是否是合法的邮件地址)、@NotNull(是否非空)等

  • 复杂类型:比如map、类等

配置文件yml还是properties他们都能获取到值;

如果说,我们只是在某个业务逻辑中需要获取一下配置文件中的某项值,使用@Value;

如果说,我们专门编写了一个javaBean来和配置文件进行映射,我们就直接使用@ConfigurationProperties;

3、配置文件注入值数据校验

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@Component
@ConfigurationProperties(prefix = "person")
@Validated
public class Person {

/**
* <bean class="Person">
* <property name="lastName" value="字面量/${key}从环境变量、配置文件中获取值/#{SpEL}"></property>
* <bean/>
*/

//lastName必须是邮箱格式
@Email
//@Value("${person.last-name}")
private String lastName;
//@Value("#{11*2}")
private Integer age;
//@Value("true")
private Boolean boss;

private Date birth;
private Map<String,Object> maps;
private List<Object> lists;
private Dog dog;

4、@PropertySource&@ImportResource&@Bean

@PropertySource:加载指定的配置文件;

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/**
* 将配置文件中配置的每一个属性的值,映射到这个组件中
* @ConfigurationProperties:告诉SpringBoot将本类中的所有属性和配置文件中相关的配置进行绑定;
* prefix = "person":配置文件中哪个下面的所有属性进行一一映射
*
* 只有这个组件是容器中的组件,才能容器提供的@ConfigurationProperties功能;
* @ConfigurationProperties(prefix = "person")默认从全局配置文件中获取值;
*
*/
@PropertySource(value = {"classpath:person.properties"})
@Component
@ConfigurationProperties(prefix = "person")
//@Validated
public class Person {

/**
* <bean class="Person">
* <property name="lastName" value="字面量/${key}从环境变量、配置文件中获取值/#{SpEL}"></property>
* <bean/>
*/

//lastName必须是邮箱格式
// @Email
//@Value("${person.last-name}")
private String lastName;
//@Value("#{11*2}")
private Integer age;
//@Value("true")
private Boolean boss;

@ImportResource:导入Spring的配置文件,让配置文件里面的内容生效;

Spring Boot里面没有Spring的配置文件,我们自己编写的配置文件,也不能自动识别;

想让Spring的配置文件生效,加载进来;@ImportResource标注在一个配置类

并且在beans.xml中配置的类不能再用properties和yml进行注入

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@ImportResource(locations = {"classpath:beans.xml"})
导入Spring的配置文件让其生效

不来编写Spring的配置文件

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<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">


<bean id="helloService" class="com.atguigu.springboot.service.HelloService"></bean>
</beans>

SpringBoot推荐给容器中添加组件的方式;推荐使用全注解的方式

1、配置类@Configuration——>Spring配置文件

2、使用@Bean给容器中添加组件

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/**
* @Configuration:指明当前类是一个配置类;就是来替代之前的Spring配置文件
*
* 在配置文件中用<bean><bean/>标签添加组件
*
*/
@Configuration
public class MyAppConfig {

//将方法的返回值添加到容器中;容器中这个组件默认的id就是方法名
@Bean
public HelloService helloService02(){
System.out.println("配置类@Bean给容器中添加组件了...");
return new HelloService();
}
}

##4、配置文件占位符

1、随机数

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${random.value}、${random.int}、${random.long}
${random.int(10)}、${random.int[1024,65536]}

2、占位符获取之前配置的值,如果没有可以是用:指定默认值

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person.last-name=张三${random.uuid}
person.age=${random.int}
person.birth=2017/12/15
person.boss=false
person.maps.k1=v1
person.maps.k2=14
person.lists=a,b,c
person.dog.name=${person.hello:hello}_dog
person.dog.age=15

5、Profile

1、多Profile文件

我们在主配置文件编写的时候,文件名可以是 application-{profile}.properties/yml

默认使用application.properties的配置;

2、yml支持多文档块方式

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server:
port: 8081
spring:
profiles:
active: prod

---
server:
port: 8083
spring:
profiles: dev


---

server:
port: 8084
spring:
profiles: prod #指定属于哪个环境

3、激活指定profile

​ 1、在配置文件中指定 spring.profiles.active=dev

​ 2、命令行:

​ java -jar spring-boot-02-config-0.0.1-SNAPSHOT.jar –spring.profiles.active=dev;

​ 可以直接在测试的时候,配置传入命令行参数

​ 3、虚拟机参数;

​ -Dspring.profiles.active=dev

​ 4、激活优先使用多profile文件,如果指定的环境在多profile没有配置,才会使用多文档块中的内容

6、配置文件加载位置

springboot 启动会扫描以下位置的application.properties或者application.yml文件作为Spring boot的默认配置文件

–file:./config/

–file:./

–classpath:/config/

–classpath:/

优先级由高到底,高优先级的配置会覆盖低优先级的配置;

SpringBoot会从这四个位置全部加载主配置文件;互补配置

==我们还可以通过spring.config.location来改变默认的配置文件位置==

项目打包好以后,我们可以使用命令行参数的形式,启动项目的时候来指定配置文件的新位置;指定配置文件和默认加载的这些配置文件共同起作用形成互补配置;

java -jar spring-boot-02-config-02-0.0.1-SNAPSHOT.jar –spring.config.location=G:/application.properties

7、外部配置加载顺序

==SpringBoot也可以从以下位置加载配置; 优先级从高到低;高优先级的配置覆盖低优先级的配置,所有的配置会形成互补配置==

1.命令行参数

所有的配置都可以在命令行上进行指定

java -jar spring-boot-02-config-02-0.0.1-SNAPSHOT.jar –server.port=8087 –server.context-path=/abc

多个配置用空格分开; –配置项=值

2.来自java:comp/env的JNDI属性

3.Java系统属性(System.getProperties())

4.操作系统环境变量

5.RandomValuePropertySource配置的random.*属性值

==由jar包外向jar包内进行寻找;==

==优先加载带profile==

6.jar包外部的application-{profile}.properties或application.yml(带spring.profile)配置文件

7.jar包内部的application-{profile}.properties或application.yml(带spring.profile)配置文件

==再来加载不带profile==

8.jar包外部的application.properties或application.yml(不带spring.profile)配置文件

9.jar包内部的application.properties或application.yml(不带spring.profile)配置文件

10.@Configuration注解类上的@PropertySource

11.通过SpringApplication.setDefaultProperties指定的默认属性

所有支持的配置加载来源;

参考官方文档

8、自动配置原理

配置文件到底能写什么?怎么写?自动配置原理;

配置文件能配置的属性参照

1、自动配置原理:

1)、SpringBoot启动的时候加载主配置类,开启了自动配置功能@EnableAutoConfiguration

2)、@EnableAutoConfiguration 作用:

  • 利用EnableAutoConfigurationImportSelector给容器中导入一些组件?
  • 可以查看selectImports()方法的内容;

  • List configurations = getCandidateConfigurations(annotationMetadata, attributes);获取候选的配置

    • SpringFactoriesLoader.loadFactoryNames()
      扫描所有jar包类路径下  META-INF/spring.factories
      把扫描到的这些文件的内容包装成properties对象
      从properties中获取到EnableAutoConfiguration.class类(类名)对应的值,然后把他们添加在容器中
      
      
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      **==将 类路径下 META-INF/spring.factories 里面配置的所有EnableAutoConfiguration的值加入到了容器中;==**

      ```properties
      # Auto Configure
      org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
      org.springframework.boot.autoconfigure.admin.SpringApplicationAdminJmxAutoConfiguration,\
      org.springframework.boot.autoconfigure.aop.AopAutoConfiguration,\
      org.springframework.boot.autoconfigure.amqp.RabbitAutoConfiguration,\
      org.springframework.boot.autoconfigure.batch.BatchAutoConfiguration,\
      org.springframework.boot.autoconfigure.cache.CacheAutoConfiguration,\
      org.springframework.boot.autoconfigure.cassandra.CassandraAutoConfiguration,\
      org.springframework.boot.autoconfigure.cloud.CloudAutoConfiguration,\
      org.springframework.boot.autoconfigure.context.ConfigurationPropertiesAutoConfiguration,\
      org.springframework.boot.autoconfigure.context.MessageSourceAutoConfiguration,\
      org.springframework.boot.autoconfigure.context.PropertyPlaceholderAutoConfiguration,\
      org.springframework.boot.autoconfigure.couchbase.CouchbaseAutoConfiguration,\
      org.springframework.boot.autoconfigure.dao.PersistenceExceptionTranslationAutoConfiguration,\
      org.springframework.boot.autoconfigure.data.cassandra.CassandraDataAutoConfiguration,\
      org.springframework.boot.autoconfigure.data.cassandra.CassandraRepositoriesAutoConfiguration,\
      org.springframework.boot.autoconfigure.data.couchbase.CouchbaseDataAutoConfiguration,\
      org.springframework.boot.autoconfigure.data.couchbase.CouchbaseRepositoriesAutoConfiguration,\
      org.springframework.boot.autoconfigure.data.elasticsearch.ElasticsearchAutoConfiguration,\
      org.springframework.boot.autoconfigure.data.elasticsearch.ElasticsearchDataAutoConfiguration,\
      org.springframework.boot.autoconfigure.data.elasticsearch.ElasticsearchRepositoriesAutoConfiguration,\
      org.springframework.boot.autoconfigure.data.jpa.JpaRepositoriesAutoConfiguration,\
      org.springframework.boot.autoconfigure.data.ldap.LdapDataAutoConfiguration,\
      org.springframework.boot.autoconfigure.data.ldap.LdapRepositoriesAutoConfiguration,\
      org.springframework.boot.autoconfigure.data.mongo.MongoDataAutoConfiguration,\
      org.springframework.boot.autoconfigure.data.mongo.MongoRepositoriesAutoConfiguration,\
      org.springframework.boot.autoconfigure.data.neo4j.Neo4jDataAutoConfiguration,\
      org.springframework.boot.autoconfigure.data.neo4j.Neo4jRepositoriesAutoConfiguration,\
      org.springframework.boot.autoconfigure.data.solr.SolrRepositoriesAutoConfiguration,\
      org.springframework.boot.autoconfigure.data.redis.RedisAutoConfiguration,\
      org.springframework.boot.autoconfigure.data.redis.RedisRepositoriesAutoConfiguration,\
      org.springframework.boot.autoconfigure.data.rest.RepositoryRestMvcAutoConfiguration,\
      org.springframework.boot.autoconfigure.data.web.SpringDataWebAutoConfiguration,\
      org.springframework.boot.autoconfigure.elasticsearch.jest.JestAutoConfiguration,\
      org.springframework.boot.autoconfigure.freemarker.FreeMarkerAutoConfiguration,\
      org.springframework.boot.autoconfigure.gson.GsonAutoConfiguration,\
      org.springframework.boot.autoconfigure.h2.H2ConsoleAutoConfiguration,\
      org.springframework.boot.autoconfigure.hateoas.HypermediaAutoConfiguration,\
      org.springframework.boot.autoconfigure.hazelcast.HazelcastAutoConfiguration,\
      org.springframework.boot.autoconfigure.hazelcast.HazelcastJpaDependencyAutoConfiguration,\
      org.springframework.boot.autoconfigure.info.ProjectInfoAutoConfiguration,\
      org.springframework.boot.autoconfigure.integration.IntegrationAutoConfiguration,\
      org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration,\
      org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration,\
      org.springframework.boot.autoconfigure.jdbc.JdbcTemplateAutoConfiguration,\
      org.springframework.boot.autoconfigure.jdbc.JndiDataSourceAutoConfiguration,\
      org.springframework.boot.autoconfigure.jdbc.XADataSourceAutoConfiguration,\
      org.springframework.boot.autoconfigure.jdbc.DataSourceTransactionManagerAutoConfiguration,\
      org.springframework.boot.autoconfigure.jms.JmsAutoConfiguration,\
      org.springframework.boot.autoconfigure.jmx.JmxAutoConfiguration,\
      org.springframework.boot.autoconfigure.jms.JndiConnectionFactoryAutoConfiguration,\
      org.springframework.boot.autoconfigure.jms.activemq.ActiveMQAutoConfiguration,\
      org.springframework.boot.autoconfigure.jms.artemis.ArtemisAutoConfiguration,\
      org.springframework.boot.autoconfigure.flyway.FlywayAutoConfiguration,\
      org.springframework.boot.autoconfigure.groovy.template.GroovyTemplateAutoConfiguration,\
      org.springframework.boot.autoconfigure.jersey.JerseyAutoConfiguration,\
      org.springframework.boot.autoconfigure.jooq.JooqAutoConfiguration,\
      org.springframework.boot.autoconfigure.kafka.KafkaAutoConfiguration,\
      org.springframework.boot.autoconfigure.ldap.embedded.EmbeddedLdapAutoConfiguration,\
      org.springframework.boot.autoconfigure.ldap.LdapAutoConfiguration,\
      org.springframework.boot.autoconfigure.liquibase.LiquibaseAutoConfiguration,\
      org.springframework.boot.autoconfigure.mail.MailSenderAutoConfiguration,\
      org.springframework.boot.autoconfigure.mail.MailSenderValidatorAutoConfiguration,\
      org.springframework.boot.autoconfigure.mobile.DeviceResolverAutoConfiguration,\
      org.springframework.boot.autoconfigure.mobile.DeviceDelegatingViewResolverAutoConfiguration,\
      org.springframework.boot.autoconfigure.mobile.SitePreferenceAutoConfiguration,\
      org.springframework.boot.autoconfigure.mongo.embedded.EmbeddedMongoAutoConfiguration,\
      org.springframework.boot.autoconfigure.mongo.MongoAutoConfiguration,\
      org.springframework.boot.autoconfigure.mustache.MustacheAutoConfiguration,\
      org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration,\
      org.springframework.boot.autoconfigure.reactor.ReactorAutoConfiguration,\
      org.springframework.boot.autoconfigure.security.SecurityAutoConfiguration,\
      org.springframework.boot.autoconfigure.security.SecurityFilterAutoConfiguration,\
      org.springframework.boot.autoconfigure.security.FallbackWebSecurityAutoConfiguration,\
      org.springframework.boot.autoconfigure.security.oauth2.OAuth2AutoConfiguration,\
      org.springframework.boot.autoconfigure.sendgrid.SendGridAutoConfiguration,\
      org.springframework.boot.autoconfigure.session.SessionAutoConfiguration,\
      org.springframework.boot.autoconfigure.social.SocialWebAutoConfiguration,\
      org.springframework.boot.autoconfigure.social.FacebookAutoConfiguration,\
      org.springframework.boot.autoconfigure.social.LinkedInAutoConfiguration,\
      org.springframework.boot.autoconfigure.social.TwitterAutoConfiguration,\
      org.springframework.boot.autoconfigure.solr.SolrAutoConfiguration,\
      org.springframework.boot.autoconfigure.thymeleaf.ThymeleafAutoConfiguration,\
      org.springframework.boot.autoconfigure.transaction.TransactionAutoConfiguration,\
      org.springframework.boot.autoconfigure.transaction.jta.JtaAutoConfiguration,\
      org.springframework.boot.autoconfigure.validation.ValidationAutoConfiguration,\
      org.springframework.boot.autoconfigure.web.DispatcherServletAutoConfiguration,\
      org.springframework.boot.autoconfigure.web.EmbeddedServletContainerAutoConfiguration,\
      org.springframework.boot.autoconfigure.web.ErrorMvcAutoConfiguration,\
      org.springframework.boot.autoconfigure.web.HttpEncodingAutoConfiguration,\
      org.springframework.boot.autoconfigure.web.HttpMessageConvertersAutoConfiguration,\
      org.springframework.boot.autoconfigure.web.MultipartAutoConfiguration,\
      org.springframework.boot.autoconfigure.web.ServerPropertiesAutoConfiguration,\
      org.springframework.boot.autoconfigure.web.WebClientAutoConfiguration,\
      org.springframework.boot.autoconfigure.web.WebMvcAutoConfiguration,\
      org.springframework.boot.autoconfigure.websocket.WebSocketAutoConfiguration,\
      org.springframework.boot.autoconfigure.websocket.WebSocketMessagingAutoConfiguration,\
      org.springframework.boot.autoconfigure.webservices.WebServicesAutoConfiguration

每一个这样的 xxxAutoConfiguration类都是容器中的一个组件,都加入到容器中;用他们来做自动配置;

3)、每一个自动配置类进行自动配置功能;

4)、以HttpEncodingAutoConfiguration(Http编码自动配置)为例解释自动配置原理;

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@Configuration   //表示这是一个配置类,以前编写的配置文件一样,也可以给容器中添加组件
@EnableConfigurationProperties(HttpEncodingProperties.class) //启动指定类的ConfigurationProperties功能;将配置文件中对应的值和HttpEncodingProperties绑定起来;并把HttpEncodingProperties加入到ioc容器中

@ConditionalOnWebApplication //Spring底层@Conditional注解(Spring注解版),根据不同的条件,如果满足指定的条件,整个配置类里面的配置就会生效; 判断当前应用是否是web应用,如果是,当前配置类生效

@ConditionalOnClass(CharacterEncodingFilter.class) //判断当前项目有没有这个类CharacterEncodingFilterSpringMVC中进行乱码解决的过滤器;

@ConditionalOnProperty(prefix = "spring.http.encoding", value = "enabled", matchIfMissing = true) //判断配置文件中是否存在某个配置 spring.http.encoding.enabled;如果不存在,判断也是成立的
//即使我们配置文件中不配置pring.http.encoding.enabled=true,也是默认生效的;
public class HttpEncodingAutoConfiguration {

//他已经和SpringBoot的配置文件映射了
private final HttpEncodingProperties properties;

//只有一个有参构造器的情况下,参数的值就会从容器中拿
public HttpEncodingAutoConfiguration(HttpEncodingProperties properties) {
this.properties = properties;
}

@Bean //给容器中添加一个组件,这个组件的某些值需要从properties中获取
@ConditionalOnMissingBean(CharacterEncodingFilter.class) //判断容器没有这个组件?
public CharacterEncodingFilter characterEncodingFilter() {
CharacterEncodingFilter filter = new OrderedCharacterEncodingFilter();
filter.setEncoding(this.properties.getCharset().name());
filter.setForceRequestEncoding(this.properties.shouldForce(Type.REQUEST));
filter.setForceResponseEncoding(this.properties.shouldForce(Type.RESPONSE));
return filter;
}

根据当前不同的条件判断,决定这个配置类是否生效?

一但这个配置类生效;这个配置类就会给容器中添加各种组件;这些组件的属性是从对应的properties类中获取的,这些类里面的每一个属性又是和配置文件绑定的;

5)、所有在配置文件中能配置的属性都是在xxxxProperties类中封装者‘;配置文件能配置什么就可以参照某个功能对应的这个属性类

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@ConfigurationProperties(prefix = "spring.http.encoding")  //从配置文件中获取指定的值和bean的属性进行绑定
public class HttpEncodingProperties {

public static final Charset DEFAULT_CHARSET = Charset.forName("UTF-8");

精髓:

1)、SpringBoot启动会加载大量的自动配置类

2)、我们看我们需要的功能有没有SpringBoot默认写好的自动配置类;

3)、我们再来看这个自动配置类中到底配置了哪些组件;(只要我们要用的组件有,我们就不需要再来配置了)

4)、给容器中自动配置类添加组件的时候,会从properties类中获取某些属性。我们就可以在配置文件中指定这些属性的值;

xxxxAutoConfigurartion:自动配置类;

给容器中添加组件

xxxxProperties:封装配置文件中相关属性;

2、细节

1、@Conditional派生注解(Spring注解版原生的@Conditional作用)

作用:必须是@Conditional指定的条件成立,才给容器中添加组件,配置配里面的所有内容才生效;

@Conditional扩展注解 作用(判断是否满足当前指定条件)
@ConditionalOnJava 系统的java版本是否符合要求
@ConditionalOnBean 容器中存在指定Bean;
@ConditionalOnMissingBean 容器中不存在指定Bean;
@ConditionalOnExpression 满足SpEL表达式指定
@ConditionalOnClass 系统中有指定的类
@ConditionalOnMissingClass 系统中没有指定的类
@ConditionalOnSingleCandidate 容器中只有一个指定的Bean,或者这个Bean是首选Bean
@ConditionalOnProperty 系统中指定的属性是否有指定的值
@ConditionalOnResource 类路径下是否存在指定资源文件
@ConditionalOnWebApplication 当前是web环境
@ConditionalOnNotWebApplication 当前不是web环境
@ConditionalOnJndi JNDI存在指定项

自动配置类必须在一定的条件下才能生效;

我们怎么知道哪些自动配置类生效;

==我们可以通过启用 debug=true属性;来让控制台打印自动配置报告==,这样我们就可以很方便的知道哪些自动配置类生效;

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=========================
AUTO-CONFIGURATION REPORT
=========================


Positive matches:(自动配置类启用的)
-----------------

DispatcherServletAutoConfiguration matched:
- @ConditionalOnClass found required class 'org.springframework.web.servlet.DispatcherServlet'; @ConditionalOnMissingClass did not find unwanted class (OnClassCondition)
- @ConditionalOnWebApplication (required) found StandardServletEnvironment (OnWebApplicationCondition)


Negative matches:(没有启动,没有匹配成功的自动配置类)
-----------------

ActiveMQAutoConfiguration:
Did not match:
- @ConditionalOnClass did not find required classes 'javax.jms.ConnectionFactory', 'org.apache.activemq.ActiveMQConnectionFactory' (OnClassCondition)

AopAutoConfiguration:
Did not match:
- @ConditionalOnClass did not find required classes 'org.aspectj.lang.annotation.Aspect', 'org.aspectj.lang.reflect.Advice' (OnClassCondition)

三、日志

1、日志框架

小张;开发一个大型系统;

​ 1、System.out.println(“”);将关键数据打印在控制台;去掉?写在一个文件?

​ 2、框架来记录系统的一些运行时信息;日志框架 ; zhanglogging.jar;

​ 3、高大上的几个功能?异步模式?自动归档?xxxx? zhanglogging-good.jar?

​ 4、将以前框架卸下来?换上新的框架,重新修改之前相关的API;zhanglogging-prefect.jar;

​ 5、JDBC—数据库驱动;

​ 写了一个统一的接口层;日志门面(日志的一个抽象层);logging-abstract.jar;

​ 给项目中导入具体的日志实现就行了;我们之前的日志框架都是实现的抽象层;

市面上的日志框架;

JUL、JCL、Jboss-logging、logback、log4j、log4j2、slf4j….

日志门面 (日志的抽象层) 日志实现
JCL(Jakarta Commons Logging) SLF4j(Simple Logging Facade for Java) jboss-logging Log4j JUL(java.util.logging) Log4j2 Logback

左边选一个门面(抽象层)、右边来选一个实现;

日志门面: SLF4J;

日志实现:Logback;

SpringBoot:底层是Spring框架,Spring框架默认是用JCL;‘

==SpringBoot选用 SLF4j和logback;==

2、SLF4j使用

1、如何在系统中使用SLF4j https://www.slf4j.org

以后开发的时候,日志记录方法的调用,不应该来直接调用日志的实现类,而是调用日志抽象层里面的方法;

给系统里面导入slf4j的jar和 logback的实现jar

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import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class HelloWorld {
public static void main(String[] args) {
Logger logger = LoggerFactory.getLogger(HelloWorld.class);
logger.info("Hello World");
}
}

图示;

images/concrete-bindings.png

每一个日志的实现框架都有自己的配置文件。使用slf4j以后,配置文件还是做成日志实现框架自己本身的配置文件;

2、遗留问题

a(slf4j+logback): Spring(commons-logging)、Hibernate(jboss-logging)、MyBatis、xxxx

统一日志记录,即使是别的框架和我一起统一使用slf4j进行输出?

如何让系统中所有的日志都统一到slf4j;

==1、将系统中其他日志框架先排除出去;==

==2、用中间包来替换原有的日志框架;==

==3、我们导入slf4j其他的实现==

3、SpringBoot日志关系

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<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>

SpringBoot使用它来做日志功能;

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<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-logging</artifactId>
</dependency>

底层依赖关系

总结:

​ 1)、SpringBoot底层也是使用slf4j+logback的方式进行日志记录

​ 2)、SpringBoot也把其他的日志都替换成了slf4j;

​ 3)、中间替换包?

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@SuppressWarnings("rawtypes")
public abstract class LogFactory {

static String UNSUPPORTED_OPERATION_IN_JCL_OVER_SLF4J = "http://www.slf4j.org/codes.html#unsupported_operation_in_jcl_over_slf4j";

static LogFactory logFactory = new SLF4JLogFactory();

​ 4)、如果我们要引入其他框架?一定要把这个框架的默认日志依赖移除掉?

​ Spring框架用的是commons-logging;

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<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<exclusions>
<exclusion>
<groupId>commons-logging</groupId>
<artifactId>commons-logging</artifactId>
</exclusion>
</exclusions>
</dependency>

==SpringBoot能自动适配所有的日志,而且底层使用slf4j+logback的方式记录日志,引入其他框架的时候,只需要把这个框架依赖的日志框架排除掉即可;==

4、日志使用;

1、默认配置

SpringBoot默认帮我们配置好了日志;

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//记录器
Logger logger = LoggerFactory.getLogger(getClass());
@Test
public void contextLoads() {
//System.out.println();

//日志的级别;
//由低到高 trace<debug<info<warn<error
//可以调整输出的日志级别;日志就只会在这个级别以以后的高级别生效
logger.trace("这是trace日志...");
logger.debug("这是debug日志...");
//SpringBoot默认给我们使用的是info级别的,没有指定级别的就用SpringBoot默认规定的级别;root级别
logger.info("这是info日志...");
logger.warn("这是warn日志...");
logger.error("这是error日志...");


}
日志输出格式:
    %d表示日期时间,
    %thread表示线程名,
    %-5level:级别从左显示5个字符宽度
    %logger{50} 表示logger名字最长50个字符,否则按照句点分割。 
    %msg:日志消息,
    %n是换行符
-->
%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{50} - %msg%n

SpringBoot修改日志的默认配置

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logging.level.com.atguigu=trace


#logging.path=
# 不指定路径在当前项目下生成springboot.log日志
# 可以指定完整的路径;
#logging.file=G:/springboot.log

# 在当前磁盘的根路径下创建spring文件夹和里面的log文件夹;使用 spring.log 作为默认文件
logging.path=/spring/log

# 在控制台输出的日志的格式
logging.pattern.console=%d{yyyy-MM-dd} [%thread] %-5level %logger{50} - %msg%n
# 指定文件中日志输出的格式
logging.pattern.file=%d{yyyy-MM-dd} === [%thread] === %-5level === %logger{50} ==== %msg%n
logging.file logging.path Example Description
(none) (none) 只在控制台输出
指定文件名 (none) my.log 输出日志到my.log文件
(none) 指定目录 /var/log 输出到指定目录的 spring.log 文件中

2、指定配置

给类路径下放上每个日志框架自己的配置文件即可;SpringBoot就不使用他默认配置的了

Logging System Customization
Logback logback-spring.xml, logback-spring.groovy, logback.xml or logback.groovy
Log4j2 log4j2-spring.xml or log4j2.xml
JDK (Java Util Logging) logging.properties

logback.xml:直接就被日志框架识别了;

logback-spring.xml:日志框架就不直接加载日志的配置项,由SpringBoot解析日志配置,可以使用SpringBoot的高级Profile功能

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<springProfile name="staging">
<!-- configuration to be enabled when the "staging" profile is active -->
可以指定某段配置只在某个环境下生效
</springProfile>

如:

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<appender name="stdout" class="ch.qos.logback.core.ConsoleAppender">
<!--
日志输出格式:
%d表示日期时间,
%thread表示线程名,
%-5level:级别从左显示5个字符宽度
%logger{50} 表示logger名字最长50个字符,否则按照句点分割。
%msg:日志消息,
%n是换行符
-->
<layout class="ch.qos.logback.classic.PatternLayout">
<springProfile name="dev">
<pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} ----> [%thread] ---> %-5level %logger{50} - %msg%n</pattern>
</springProfile>
<springProfile name="!dev">
<pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} ==== [%thread] ==== %-5level %logger{50} - %msg%n</pattern>
</springProfile>
</layout>
</appender>

如果使用logback.xml作为日志配置文件,还要使用profile功能,会有以下错误

no applicable action for [springProfile]

5、切换日志框架

可以按照slf4j的日志适配图,进行相关的切换;

slf4j+log4j的方式;

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<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<exclusions>
<exclusion>
<artifactId>logback-classic</artifactId>
<groupId>ch.qos.logback</groupId>
</exclusion>
<exclusion>
<artifactId>log4j-over-slf4j</artifactId>
<groupId>org.slf4j</groupId>
</exclusion>
</exclusions>
</dependency>

<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
</dependency>

切换为log4j2

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   <dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<exclusions>
<exclusion>
<artifactId>spring-boot-starter-logging</artifactId>
<groupId>org.springframework.boot</groupId>
</exclusion>
</exclusions>
</dependency>

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-log4j2</artifactId>
</dependency>

四、Web开发

1、简介

使用SpringBoot;

1)、创建SpringBoot应用,选中我们需要的模块;

2)、SpringBoot已经默认将这些场景配置好了,只需要在配置文件中指定少量配置就可以运行起来

3)、自己编写业务代码;

自动配置原理?

这个场景SpringBoot帮我们配置了什么?能不能修改?能修改哪些配置?能不能扩展?xxx

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xxxxAutoConfiguration:帮我们给容器中自动配置组件;
xxxxProperties:配置类来封装配置文件的内容;

2、SpringBoot对静态资源的映射规则;

ResourceProperties定义了静态资源的访问路径,还可以设置和静态资源有关的参数,缓存时间等

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@ConfigurationProperties(prefix = "spring.resources", ignoreUnknownFields = false)
public class ResourceProperties implements ResourceLoaderAware {
//静态资源的访问路径
private static final String[] CLASSPATH_RESOURCE_LOCATIONS = { "classpath:/META-INF/resources/",
"classpath:/resources/", "classpath:/static/", "classpath:/public/" };

/**
* Locations of static resources. Defaults to classpath:[/META-INF/resources/,
* /resources/, /static/, /public/].
*/
private String[] staticLocations = CLASSPATH_RESOURCE_LOCATIONS;


//还可以设置和静态资源有关的参数,缓存时间等
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WebMvcAuotConfiguration:
@Override
public void addResourceHandlers(ResourceHandlerRegistry registry) {
if (!this.resourceProperties.isAddMappings()) {
logger.debug("Default resource handling disabled");
return;
}
Integer cachePeriod = this.resourceProperties.getCachePeriod();
if (!registry.hasMappingForPattern("/webjars/**")) {
customizeResourceHandlerRegistration(
registry.addResourceHandler("/webjars/**")
.addResourceLocations(
"classpath:/META-INF/resources/webjars/")
.setCachePeriod(cachePeriod));
}
String staticPathPattern = this.mvcProperties.getStaticPathPattern();
//静态资源文件夹映射
if (!registry.hasMappingForPattern(staticPathPattern)) {
customizeResourceHandlerRegistration(
registry.addResourceHandler(staticPathPattern)
.addResourceLocations(
this.resourceProperties.getStaticLocations())
.setCachePeriod(cachePeriod));
}
}

//配置欢迎页映射
@Bean
public WelcomePageHandlerMapping welcomePageHandlerMapping(
ResourceProperties resourceProperties) {
return new WelcomePageHandlerMapping(resourceProperties.getWelcomePage(),
this.mvcProperties.getStaticPathPattern());
}

//配置喜欢的图标
@Configuration
@ConditionalOnProperty(value = "spring.mvc.favicon.enabled", matchIfMissing = true)
public static class FaviconConfiguration {

private final ResourceProperties resourceProperties;

public FaviconConfiguration(ResourceProperties resourceProperties) {
this.resourceProperties = resourceProperties;
}

@Bean
public SimpleUrlHandlerMapping faviconHandlerMapping() {
SimpleUrlHandlerMapping mapping = new SimpleUrlHandlerMapping();
mapping.setOrder(Ordered.HIGHEST_PRECEDENCE + 1);
//所有 **/favicon.ico
mapping.setUrlMap(Collections.singletonMap("**/favicon.ico",
faviconRequestHandler()));
return mapping;
}

@Bean
public ResourceHttpRequestHandler faviconRequestHandler() {
ResourceHttpRequestHandler requestHandler = new ResourceHttpRequestHandler();
requestHandler
.setLocations(this.resourceProperties.getFaviconLocations());
return requestHandler;
}

}

1)、所有 /webjars/** ,都去 classpath:/META-INF/resources/webjars/ 找资源;

​ webjars:以jar包的方式引入静态资源;

http://www.webjars.org/

localhost:8080/webjars/jquery/3.3.1/jquery.js

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<!--引入jquery-webjar-->在访问的时候只需要写webjars下面资源的名称即可
<dependency>
<groupId>org.webjars</groupId>
<artifactId>jquery</artifactId>
<version>3.3.1</version>
</dependency>

2)、”/**” 访问当前项目的任何资源,都去(静态资源的文件夹)找映射

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"classpath:/META-INF/resources/", 
"classpath:/resources/",
"classpath:/static/",
"classpath:/public/"
"/":当前项目的根路径

localhost:8080/abc:去静态资源文件夹里面找abc

如果想要修改静态资源文件夹路径,可以在properties文件中配置spring.resources.static-locations属性指定,指定之后默认文件夹会失效。

3)、欢迎页; 静态资源文件夹下的所有index.html页面;被”/**”映射;

​ localhost:8080/ 找index页面

4)、所有的 **/favicon.ico 都是在静态资源文件下找(如果替换之后不生效可在浏览器ctrl+f5刷新);

3、模板引擎

JSP、Velocity、Freemarker、Thymeleaf

SpringBoot推荐的Thymeleaf;

语法更简单,功能更强大;

1、引入thymeleaf;

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		<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
2.1.6
</dependency>
切换thymeleaf版本
<properties>
<thymeleaf.version>3.0.9.RELEASE</thymeleaf.version>
<!-- 布局功能的支持程序 thymeleaf3主程序 layout2以上版本 -->
<!-- thymeleaf2 layout1-->
<thymeleaf-layout-dialect.version>2.2.2</thymeleaf-layout-dialect.version>
</properties>

2、Thymeleaf使用

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@ConfigurationProperties(prefix = "spring.thymeleaf")
public class ThymeleafProperties {

private static final Charset DEFAULT_ENCODING = Charset.forName("UTF-8");

private static final MimeType DEFAULT_CONTENT_TYPE = MimeType.valueOf("text/html");

public static final String DEFAULT_PREFIX = "classpath:/templates/";

public static final String DEFAULT_SUFFIX = ".html";
//

只要我们把HTML页面放在classpath:/templates/,thymeleaf就能自动渲染;

使用:

1、导入thymeleaf的名称空间

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<html lang="en" xmlns:th="http://www.thymeleaf.org">

2、使用thymeleaf语法;

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<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<h1>成功!</h1>
<!--th:text 将div里面的文本内容设置为 -->
<div th:text="${hello}">这是显示欢迎信息</div>
</body>
</html>

3、语法规则

1)、th:text;改变当前元素里面的文本内容;

​ th:任意html属性;来替换原生属性的值

2)、表达式?

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Simple expressions:(表达式语法)
Variable Expressions: ${...}:获取变量值;OGNL;
1)、获取对象的属性、调用方法
2)、使用内置的基本对象:
#ctx : the context object.
#vars: the context variables.
#locale : the context locale.
#request : (only in Web Contexts) the HttpServletRequest object.
#response : (only in Web Contexts) the HttpServletResponse object.
#session : (only in Web Contexts) the HttpSession object.
#servletContext : (only in Web Contexts) the ServletContext object.

${session.foo}
3)、内置的一些工具对象:
#execInfo : information about the template being processed.
#messages : methods for obtaining externalized messages inside variables expressions, in the same way as they would be obtained using #{…} syntax.
#uris : methods for escaping parts of URLs/URIs
#conversions : methods for executing the configured conversion service (if any).
#dates : methods for java.util.Date objects: formatting, component extraction, etc.
#calendars : analogous to #dates , but for java.util.Calendar objects.
#numbers : methods for formatting numeric objects.
#strings : methods for String objects: contains, startsWith, prepending/appending, etc.
#objects : methods for objects in general.
#bools : methods for boolean evaluation.
#arrays : methods for arrays.
#lists : methods for lists.
#sets : methods for sets.
#maps : methods for maps.
#aggregates : methods for creating aggregates on arrays or collections.
#ids : methods for dealing with id attributes that might be repeated (for example, as a result of an iteration).

Selection Variable Expressions: *{...}:选择表达式:和${}在功能上是一样;
补充:配合 th:object="${session.user}:
<div th:object="${session.user}">
<p>Name: <span th:text="*{firstName}">Sebastian</span>.</p>
<p>Surname: <span th:text="*{lastName}">Pepper</span>.</p>
<p>Nationality: <span th:text="*{nationality}">Saturn</span>.</p>
</div>

Message Expressions: #{...}:获取国际化内容
Link URL Expressions: @{...}:定义URL;
@{/order/process(execId=${execId},execType='FAST')}
Fragment Expressions: ~{...}:片段引用表达式
<div th:insert="~{commons :: main}">...</div>

Literals(字面量)
Text literals: 'one text' , 'Another one!' ,…
Number literals: 0 , 34 , 3.0 , 12.3 ,…
Boolean literals: true , false
Null literal: null
Literal tokens: one , sometext , main ,…
Text operations:(文本操作)
String concatenation: +
Literal substitutions: |The name is ${name}|
Arithmetic operations:(数学运算)
Binary operators: + , - , * , / , %
Minus sign (unary operator): -
Boolean operations:(布尔运算)
Binary operators: and , or
Boolean negation (unary operator): ! , not
Comparisons and equality:(比较运算)
Comparators: > , < , >= , <= ( gt , lt , ge , le )
Equality operators: == , != ( eq , ne )
Conditional operators:条件运算(三元运算符)
If-then: (if) ? (then)
If-then-else: (if) ? (then) : (else)
Default: (value) ?: (defaultvalue)
Special tokens:
No-Operation: _

4、SpringMVC自动配置

https://docs.spring.io/spring-boot/docs/1.5.10.RELEASE/reference/htmlsingle/#boot-features-developing-web-applications

1. Spring MVC auto-configuration

Spring Boot 自动配置好了SpringMVC

以下是SpringBoot对SpringMVC的默认配置:==(WebMvcAutoConfiguration)==

  • Inclusion of ContentNegotiatingViewResolver and BeanNameViewResolver beans.

    • 自动配置了ViewResolver(视图解析器:根据方法的返回值得到视图对象(View),视图对象决定如何渲染(转发?重定向?))
    • ContentNegotiatingViewResolver:组合所有的视图解析器的;
    • ==如何定制:我们可以自己给容器中添加一个视图解析器;自动的将其组合进来;==
  • Support for serving static resources, including support for WebJars (see below).静态资源文件夹路径,webjars

  • Static index.html support. 静态首页访问

  • Custom Favicon support (see below). favicon.ico

  • 自动注册了 of Converter, GenericConverter, Formatter beans.

    • Converter:转换器; public String hello(User user):类型转换使用Converter
    • Formatter 格式化器; 2017.12.17===Date;
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@Bean
@ConditionalOnProperty(prefix = "spring.mvc", name = "date-format")//在文件中配置日期格式化的规则
public Formatter<Date> dateFormatter() {
return new DateFormatter(this.mvcProperties.getDateFormat());//日期格式化组件
}

​ ==自己添加的格式化器转换器,我们只需要放在容器中即可==

  • Support for HttpMessageConverters (see below).

    • HttpMessageConverter:SpringMVC用来转换Http请求和响应的;User—Json;

    • HttpMessageConverters 是从容器中确定;获取所有的HttpMessageConverter;

      ==自己给容器中添加HttpMessageConverter,只需要将自己的组件注册容器中(@Bean,@Component)==

  • Automatic registration of MessageCodesResolver (see below).定义错误代码生成规则

  • Automatic use of a ConfigurableWebBindingInitializer bean (see below).

    ==我们可以配置一个ConfigurableWebBindingInitializer来替换默认的;(添加到容器)==

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    初始化WebDataBinder;
    请求数据=====JavaBean;

org.springframework.boot.autoconfigure.web:web的所有自动场景;

If you want to keep Spring Boot MVC features, and you just want to add additional MVC configuration (interceptors, formatters, view controllers etc.) you can add your own @Configuration class of type WebMvcConfigurerAdapter, but without @EnableWebMvc. If you wish to provide custom instances of RequestMappingHandlerMapping, RequestMappingHandlerAdapter or ExceptionHandlerExceptionResolver you can declare a WebMvcRegistrationsAdapter instance providing such components.

If you want to take complete control of Spring MVC, you can add your own @Configuration annotated with @EnableWebMvc.

2、扩展SpringMVC

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<mvc:view-controller path="/hello" view-name="success"/>
<mvc:interceptors>
<mvc:interceptor>
<mvc:mapping path="/hello"/>
<bean></bean>
</mvc:interceptor>
</mvc:interceptors>

编写一个配置类(@Configuration),实现接口WebMvcConfigurer;不能标注@EnableWebMvc;

既保留了所有的自动配置,也能用我们扩展的配置;

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//使用WebMvcConfigurer可以来扩展SpringMVC的功能
@Configuration
public class MyMvcConfig implements WebMvcConfigurer {
@Override
public void addViewControllers(ViewControllerRegistry registry) {
registry.addViewController("/config").setViewName("success");
}
}

原理:

​ 1)、WebMvcAutoConfiguration是SpringMVC的自动配置类

​ 2)、在做其他自动配置时会导入;WebMvcAutoConfiguration的内部类中有@Import(EnableWebMvcConfiguration.class)

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	@Configuration(proxyBeanMethods = false)
@Import(EnableWebMvcConfiguration.class)
@EnableConfigurationProperties({ WebMvcProperties.class, ResourceProperties.class })
@Order(0)
public static class WebMvcAutoConfigurationAdapter implements WebMvcConfigurer {

-----------------------------------------------------------------------------------------

@Configuration(proxyBeanMethods = false)
public static class EnableWebMvcConfiguration extends DelegatingWebMvcConfiguration implements ResourceLoaderAware {

-----------------------------------------------------------------------------------------

@Configuration(proxyBeanMethods = false)
public class DelegatingWebMvcConfiguration extends WebMvcConfigurationSupport {

private final WebMvcConfigurerComposite configurers = new WebMvcConfigurerComposite();


@Autowired(required = false)
public void setConfigurers(List<WebMvcConfigurer> configurers) {
if (!CollectionUtils.isEmpty(configurers)) {
this.configurers.addWebMvcConfigurers(configurers);
}
}

@Override
protected void addViewControllers(ViewControllerRegistry registry) {
this.configurers.addViewControllers(registry);
}

-----------------------------------------------------------------------------------------

class WebMvcConfigurerComposite implements WebMvcConfigurer {

private final List<WebMvcConfigurer> delegates = new ArrayList<>();


public void addWebMvcConfigurers(List<WebMvcConfigurer> configurers) {
if (!CollectionUtils.isEmpty(configurers)) {
this.delegates.addAll(configurers);
}
}

@Override
public void addViewControllers(ViewControllerRegistry registry) {
for (WebMvcConfigurer delegate : this.delegates) {
delegate.addViewControllers(registry);
}
}

​ 3)、容器中所有的WebMvcConfigurer都会一起起作用;

​ 4)、我们的配置类也会被调用;

​ 效果:SpringMVC的自动配置和我们的扩展配置都会起作用;

3、全面接管SpringMVC;

SpringBoot对SpringMVC的自动配置不需要了,所有都是我们自己配置;所有的SpringMVC的自动配置都失效了

我们需要在配置类中添加@EnableWebMvc即可;

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//使用WebMvcConfigurerAdapter可以来扩展SpringMVC的功能
@EnableWebMvc
@Configuration
public class MyMvcConfig extends WebMvcConfigurerAdapter {

@Override
public void addViewControllers(ViewControllerRegistry registry) {
// super.addViewControllers(registry);
//浏览器发送 /atguigu 请求来到 success
registry.addViewController("/atguigu").setViewName("success");
}
}

原理:

为什么@EnableWebMvc自动配置就失效了;

1)@EnableWebMvc的核心

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@Import(DelegatingWebMvcConfiguration.class)
public @interface EnableWebMvc {

2)、

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@Configuration
public class DelegatingWebMvcConfiguration extends WebMvcConfigurationSupport {

3)、

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@Configuration
@ConditionalOnWebApplication
@ConditionalOnClass({ Servlet.class, DispatcherServlet.class,
WebMvcConfigurerAdapter.class })
//容器中没有这个组件的时候,这个自动配置类才生效
@ConditionalOnMissingBean(WebMvcConfigurationSupport.class)
@AutoConfigureOrder(Ordered.HIGHEST_PRECEDENCE + 10)
@AutoConfigureAfter({ DispatcherServletAutoConfiguration.class,
ValidationAutoConfiguration.class })
public class WebMvcAutoConfiguration {

4)、@EnableWebMvc将WebMvcConfigurationSupport组件导入进来;

5)、导入的WebMvcConfigurationSupport只是SpringMVC最基本的功能;

5、如何修改SpringBoot的默认配置

模式:

​ 1)、SpringBoot在自动配置很多组件的时候,先看容器中有没有用户自己配置的(@Bean、@Component)如果有就用用户配置的,如果没有,才自动配置;如果有些组件可以有多个(ViewResolver)将用户配置的和自己默认的组合起来;

​ 2)、在SpringBoot中会有非常多的xxxConfigurer帮助我们进行扩展配置 ==

​ 3)、在SpringBoot中会有很多的xxxCustomizer帮助我们进行定制配置

6、RestfulCRUD

1)、默认访问首页

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//使用WebMvcConfigurerAdapter可以来扩展SpringMVC的功能
//@EnableWebMvc 不要接管SpringMVC
@Configuration
public class MyMvcConfig extends WebMvcConfigurerAdapter {

//第一种导入组件的方式
@Override
public void addViewControllers(ViewControllerRegistry registry) {
// super.addViewControllers(registry);
//浏览器发送 /atguigu 请求来到 success
registry.addViewController("/atguigu").setViewName("success");
}

//第二种导入组件的方式
//所有的WebMvcConfigurerAdapter组件都会一起起作用
@Bean //将组件注册在容器
public WebMvcConfigurerAdapter webMvcConfigurerAdapter(){
WebMvcConfigurerAdapter adapter = new WebMvcConfigurerAdapter() {
@Override
public void addViewControllers(ViewControllerRegistry registry) {
registry.addViewController("/").setViewName("login");
registry.addViewController("/index.html").setViewName("login");
}
};
return adapter;
}
}

2)、国际化

1)、编写国际化配置文件;

2)、使用ResourceBundleMessageSource管理国际化资源文件

3)、在页面使用fmt:message取出国际化内容

步骤:

1)、编写国际化配置文件,抽取页面需要显示的国际化消息

2)、SpringBoot自动配置好了管理国际化资源文件的组件,需要在spring配置文件中指定国际化配置文件的位置;

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spring.messages.basename=i18n/login
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@ConfigurationProperties(prefix = "spring.messages")
public class MessageSourceAutoConfiguration {

/**
* Comma-separated list of basenames (essentially a fully-qualified classpath
* location), each following the ResourceBundle convention with relaxed support for
* slash based locations. If it doesn't contain a package qualifier (such as
* "org.mypackage"), it will be resolved from the classpath root.
*/
private String basename = "messages";
//我们的配置文件可以直接放在类路径下叫messages.properties;

@Bean
public MessageSource messageSource() {
ResourceBundleMessageSource messageSource = new ResourceBundleMessageSource();
if (StringUtils.hasText(this.basename)) {
//设置国际化资源文件的基础名(去掉语言国家代码的)
messageSource.setBasenames(StringUtils.commaDelimitedListToStringArray(
StringUtils.trimAllWhitespace(this.basename)));
}
if (this.encoding != null) {
messageSource.setDefaultEncoding(this.encoding.name());
}
messageSource.setFallbackToSystemLocale(this.fallbackToSystemLocale);
messageSource.setCacheSeconds(this.cacheSeconds);
messageSource.setAlwaysUseMessageFormat(this.alwaysUseMessageFormat);
return messageSource;
}

3)、去页面获取国际化的值;

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<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<meta name="description" content="">
<meta name="author" content="">
<title>Signin Template for Bootstrap</title>
<!-- Bootstrap core CSS -->
<link href="asserts/css/bootstrap.min.css" th:href="@{/webjars/bootstrap/4.0.0/css/bootstrap.css}" rel="stylesheet">
<!-- Custom styles for this template -->
<link href="asserts/css/signin.css" th:href="@{/asserts/css/signin.css}" rel="stylesheet">
</head>

<body class="text-center">
<form class="form-signin" action="dashboard.html">
<img class="mb-4" th:src="@{/asserts/img/bootstrap-solid.svg}" src="asserts/img/bootstrap-solid.svg" alt="" width="72" height="72">
<h1 class="h3 mb-3 font-weight-normal" th:text="#{login.tip}">Please sign in</h1>
<label class="sr-only" th:text="#{login.username}">Username</label>
<input type="text" class="form-control" placeholder="Username" th:placeholder="#{login.username}" required="" autofocus="">
<label class="sr-only" th:text="#{login.password}">Password</label>
<input type="password" class="form-control" placeholder="Password" th:placeholder="#{login.password}" required="">
<div class="checkbox mb-3">
<label>
<input type="checkbox" value="remember-me"/> [[#{login.remember}]]
</label>
</div>
<button class="btn btn-lg btn-primary btn-block" type="submit" th:text="#{login.btn}">Sign in</button>
<p class="mt-5 mb-3 text-muted">© 2017-2018</p>
<a class="btn btn-sm">中文</a>
<a class="btn btn-sm">English</a>
</form>

</body>

</html>

效果:根据浏览器语言设置的信息切换了国际化;

原理:

​ 国际化Locale(区域信息对象);LocaleResolver(获取区域信息对象);

​ 如果设置了spring.mvc.locale属性且设置为固定解析,并且则使用固定属性,否则默认从请求头中获取。

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#设置locale区域信息
spring.mvc.locale=en_US
spring.mvc.locale-resolver=fixed
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public class WebMvcAutoConfiguration {
@Bean
@ConditionalOnMissingBean
@ConditionalOnProperty(prefix = "spring.mvc", name = "locale")
public LocaleResolver localeResolver() {
if (this.mvcProperties
.getLocaleResolver() == WebMvcProperties.LocaleResolver.FIXED) {
return new FixedLocaleResolver(this.mvcProperties.getLocale());
}
AcceptHeaderLocaleResolver localeResolver = new AcceptHeaderLocaleResolver();
localeResolver.setDefaultLocale(this.mvcProperties.getLocale());
return localeResolver;
}
-----------------------------------------------------------------------------------------
public class AcceptHeaderLocaleResolver implements LocaleResolver {

private final List<Locale> supportedLocales = new ArrayList<>(4);

@Override
public Locale resolveLocale(HttpServletRequest request) {
Locale defaultLocale = getDefaultLocale();
if (defaultLocale != null && request.getHeader("Accept-Language") == null) {
return defaultLocale;
}
Locale requestLocale = request.getLocale();
List<Locale> supportedLocales = getSupportedLocales();
if (supportedLocales.isEmpty() || supportedLocales.contains(requestLocale)) {
return requestLocale;
}
Locale supportedLocale = findSupportedLocale(request, supportedLocales);
if (supportedLocale != null) {
return supportedLocale;
}
return (defaultLocale != null ? defaultLocale : requestLocale);
}

4)、点击链接切换国际化

在页面按钮处添加超链接并带有区域信息

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<a class="btn btn-sm" th:href="@{/index.html(locale='zh_CN')}">中文</a>
<a class="btn btn-sm" th:href="@{/index.html(locale='en_US')}">English</a>
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/**
* 可以在连接上携带区域信息
*/
public class MyLocaleResolver implements LocaleResolver {

@Override
public Locale resolveLocale(HttpServletRequest request) {
String l = request.getParameter("l");
Locale locale = Locale.getDefault();
if(!StringUtils.isEmpty(l)){
String[] split = l.split("_");
locale = new Locale(split[0],split[1]);
}
return locale;
}

@Override
public void setLocale(HttpServletRequest request, HttpServletResponse response, Locale locale) {

}
}

//在配置类中添加
@Bean
public LocaleResolver localeResolver(){
return new MyLocaleResolver();
}
}

3)、登陆

开发期间模板引擎页面修改以后,要实时生效

1)、禁用模板引擎的缓存

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# 禁用缓存
spring.thymeleaf.cache=false

2)、页面修改完成以后ctrl+f9:重新编译;

用户名密码校验

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@Controller
public class LoginController {
@PostMapping("/user/login")
public String login(@RequestParam String username, @RequestParam String password, Map<String,Object> map) {
if (username.equals("mhs") && password.equals("123") ) {
//为防止页面刷新表单重复提交,使用重定向功能
return "redirect:/main.html";
}else {
map.put("msg", "用户名密码错误");
return "login";
}
}
}

登陆错误消息的显示

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<p style="color: red" th:text="${msg}" th:if="${not #strings.isEmpty(msg)}"></p>

4)、拦截器进行登陆检查

拦截器

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/**
* 登陆检查,
*/
public class LoginHandlerInterceptor implements HandlerInterceptor {
//目标方法执行之前
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
Object user = request.getSession().getAttribute("loginUser");
if(user == null){
//未登陆,返回登陆页面
request.setAttribute("msg","没有权限请先登陆");
request.getRequestDispatcher("/index.html").forward(request,response);
return false;
}else{
//已登陆,放行请求
return true;
}

}

@Override
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {

}

@Override
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {

}
}

注册拦截器

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//所有的WebMvcConfigurerAdapter组件都会一起起作用
@Bean //将组件注册在容器
public WebMvcConfigurerAdapter webMvcConfigurerAdapter(){
WebMvcConfigurerAdapter adapter = new WebMvcConfigurerAdapter() {
@Override
public void addViewControllers(ViewControllerRegistry registry) {
registry.addViewController("/").setViewName("login");
registry.addViewController("/index.html").setViewName("login");
registry.addViewController("/main.html").setViewName("dashboard");
}

//注册拦截器
@Override
public void addInterceptors(InterceptorRegistry registry) {
//super.addInterceptors(registry);
//静态资源; *.css , *.js
//SpringBoot已经做好了静态资源映射
registry.addInterceptor(new LoginHandlerInterceptor()).addPathPatterns("/**")
.excludePathPatterns("/index.html","/","/user/login");
}
};
return adapter;
}

5)、CRUD-员工列表

实验要求:

1)、RestfulCRUD:CRUD满足Rest风格;

URI: /资源名称/资源标识 HTTP请求方式区分对资源CRUD操作

普通CRUD(uri来区分操作) RestfulCRUD
查询 getEmp emp—GET
添加 addEmp?xxx emp—POST
修改 updateEmp?id=xxx&xxx=xx emp/{id}—PUT
删除 deleteEmp?id=1 emp/{id}—DELETE

2)、实验的请求架构;

实验功能 请求URI 请求方式
查询所有员工 emps GET
查询某个员工(来到修改页面) emp/1 GET
来到添加页面 emp GET
添加员工 emp POST
来到修改页面(查出员工进行信息回显) emp/1 GET
修改员工 emp PUT
删除员工 emp/1 DELETE

3)、员工列表:

thymeleaf公共页面元素抽取

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1、抽取公共片段
<div th:fragment="copy">
&copy; 2011 The Good Thymes Virtual Grocery
</div>

2、引入公共片段
<div th:insert="~{footer :: copy}"></div>
~{templatename::selector}:模板名::选择器
~{templatename::fragmentname}:模板名::片段名

3、默认效果:
insert的公共片段在div标签中
如果使用th:insert等属性进行引入,可以不用写~{}:
行内写法可以加上:[[~{}]];[(~{})];

三种引入公共片段的th属性:

th:insert:将公共片段整个插入到声明引入的元素中

th:replace:将声明引入的元素替换为公共片段

th:include:将被引入的片段的内容包含进这个标签中

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<footer th:fragment="copy">
&copy; 2011 The Good Thymes Virtual Grocery
</footer>

引入方式
<div th:insert="footer :: copy"></div>
<div th:replace="footer :: copy"></div>
<div th:include="footer :: copy"></div>

效果
<div>
<footer>
&copy; 2011 The Good Thymes Virtual Grocery
</footer>
</div>

<footer>
&copy; 2011 The Good Thymes Virtual Grocery
</footer>

<div>
&copy; 2011 The Good Thymes Virtual Grocery
</div>

侧面栏点击时自动高亮的问题

引入片段的时候传入参数: 在sidebar页面进行uri判断

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<a class="nav-link active"
th:class="${activeUri=='main.html'?'nav-link active':'nav-link'}"></a>

在引入页面传入参数

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<div th:replace="~{common/side::sidebar(activeUri='main.html')}"/>
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<nav class="col-md-2 d-none d-md-block bg-light sidebar" id="sidebar">
<div class="sidebar-sticky">
<ul class="nav flex-column">
<li class="nav-item">
<a class="nav-link active"
th:class="${activeUri=='main.html'?'nav-link active':'nav-link'}"
href="#" th:href="@{/main.html}">
<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="feather feather-home">
<path d="M3 9l9-7 9 7v11a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2z"></path>
<polyline points="9 22 9 12 15 12 15 22"></polyline>
</svg>
Dashboard <span class="sr-only">(current)</span>
</a>
</li>

<!--引入侧边栏;传入参数-->
<div th:replace="~{common/side::sidebar(activeUri='main.html')}"/>

员工列表显示

使用th:each遍历并进行性别判断和日期格式转换,并且添加编辑员工的按钮

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<h2><button type="button" class="btn btn-sm btn-success">员工添加</button> </h2>
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<tr th:each="emp:${emps}">
<td>[[${emp.id}]]</td>
<td>[[${emp.lastName}]]</td>
<td>[[${emp.email}]]</td>
<td>[[${emp.gender==0?"男":"女"}]]</td>
<td>[[${emp.department.departmentName}]]</td>
<td th:text="${#dates.format(emp.birth,'yyyy-MM-dd HH:mm')}"></td>
<td>
<button type="button" class="btn btn-sm btn-primary">编辑</button>
<button type="button" class="btn btn-sm btn-danger">删除</button>
</td>
</tr>

6)、CRUD-员工添加

添加页面

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 <form th:action="@{/emp}" th:method="post">
<div class="form-group">
<label>LastName</label>
<input type="text" class="form-control" placeholder="zhangsan" name="lastName">
</div>
<div class="form-group">
<label>Email</label>
<input type="email" class="form-control" placeholder="zhangsan@atguigu.com" name="email">
</div>
<div class="form-group">
<label name="gender">Gender</label><br/>
<div class="form-check form-check-inline">
<input class="form-check-input" type="radio" name="gender" value="1">
<label class="form-check-label"></label>
</div>
<div class="form-check form-check-inline">
<input class="form-check-input" type="radio" name="gender" value="0">
<label class="form-check-label"></label>
</div>
</div>
<div class="form-group">
<label>department</label>
<select class="form-control" name="department.id">
<option th:each="department:${departments}" th:text="${department.id}" ></option>
</select>
</div>
<div class="form-group">
<label>Birth</label>
<input type="text" class="form-control" placeholder="2000/01/30" name="birth">
</div>
<button type="submit" class="btn btn-primary">添加</button>
</form>

后台代码

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@GetMapping("/emp")
public String toAddPage(Model model) {
Collection<Department> departments = departmentDao.getDepartments();
model.addAttribute("departments", departments);
return "emp/add";
}

@PostMapping("/emp")
public String addEmp(Employee employee) {
employeeDao.save(employee);
return "redirect:/emps";
}

由于直接返回字符串默认转发给模板引擎处理,因此在要使用转发/重定向。

提交表单格式的问题

  1. 要想让表单各项数据能直接封装进employee对象,必须保证各表单项的name属性值和Javabean属性名一致。
  2. 提交日期的默认格式为yyyy/MM/dd,否则会报错。

可通过修改spring配置文件修改

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#指定表单日期提交格式
spring.mvc.date-format=yyyy-MM-dd

日期格式设置原理

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//在WebMvcAutoConfiguration类中有以下方法
@Bean
@Override
public FormattingConversionService mvcConversionService() {
WebConversionService conversionService = new WebConversionService(this.mvcProperties.getDateFormat());
addFormatters(conversionService);
return conversionService;
}

关于contoller返回值前缀可用于转发/重定向原理

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public class ThymeleafViewResolver extends AbstractCachingViewResolver implements Ordered {
protected View createView(String viewName, Locale locale) throws Exception {
if (!this.alwaysProcessRedirectAndForward && !this.canHandle(viewName, locale)) {
vrlogger.trace("[THYMELEAF] View \"{}\" cannot be handled by ThymeleafViewResolver. Passing on to the next resolver in the chain.", viewName);
return null;
} else {
String forwardUrl;
if (viewName.startsWith("redirect:")) {
vrlogger.trace("[THYMELEAF] View \"{}\" is a redirect, and will not be handled directly by ThymeleafViewResolver.", viewName);
forwardUrl = viewName.substring("redirect:".length(), viewName.length());
RedirectView view = new RedirectView(forwardUrl, this.isRedirectContextRelative(), this.isRedirectHttp10Compatible());
return (View)this.getApplicationContext().getAutowireCapableBeanFactory().initializeBean(view, viewName);
} else if (viewName.startsWith("forward:")) {
vrlogger.trace("[THYMELEAF] View \"{}\" is a forward, and will not be handled directly by ThymeleafViewResolver.", viewName);
forwardUrl = viewName.substring("forward:".length(), viewName.length());
return new InternalResourceView(forwardUrl);
} else if (this.alwaysProcessRedirectAndForward && !this.canHandle(viewName, locale)) {
vrlogger.trace("[THYMELEAF] View \"{}\" cannot be handled by ThymeleafViewResolver. Passing on to the next resolver in the chain.", viewName);
return null;
} else {
vrlogger.trace("[THYMELEAF] View {} will be handled by ThymeleafViewResolver and a {} instance will be created for it", viewName, this.getViewClass().getSimpleName());
return this.loadView(viewName, locale);
}
}
}

以上着重有以下几行

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if (viewName.startsWith("redirect:")) {
...
//如果以"redirect:",则url截取之后的部分
forwardUrl = viewName.substring("redirect:".length(), viewName.length());
//创建RedirectView并返回
RedirectView view = new RedirectView(forwardUrl, this.isRedirectContextRelative(), this.isRedirectHttp10Compatible());
...
} else if (viewName.startsWith("forward:")) {
//如果以"redirect:",则url依然截取之后的部分
forwardUrl = viewName.substring("forward:".length(), viewName.length());
//返回InternalResourceView
return new InternalResourceView(forwardUrl);
} else {
//否则直接通过viewName加载视图
return this.loadView(viewName, locale);
}

之后可以通过RedirectView和InternalResourceView看到Servlet原生API

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public class RedirectView extends AbstractUrlBasedView implements SmartView {
/**
* Convert model to request parameters and redirect to the given URL.
* @see #appendQueryProperties
* @see #sendRedirect
*/
@Override
protected void renderMergedOutputModel(Map<String, Object> model, HttpServletRequest request,
HttpServletResponse response) throws IOException {

String targetUrl = createTargetUrl(model, request);
targetUrl = updateTargetUrl(targetUrl, model, request, response);

// Save flash attributes
RequestContextUtils.saveOutputFlashMap(targetUrl, request, response);

// Redirect
sendRedirect(request, response, targetUrl, this.http10Compatible);
}

protected void sendRedirect(HttpServletRequest request, HttpServletResponse response,
String targetUrl, boolean http10Compatible) throws IOException {

String encodedURL = (isRemoteHost(targetUrl) ? targetUrl : response.encodeRedirectURL(targetUrl));
if (http10Compatible) {
HttpStatus attributeStatusCode = (HttpStatus) request.getAttribute(View.RESPONSE_STATUS_ATTRIBUTE);
if (this.statusCode != null) {
response.setStatus(this.statusCode.value());
response.setHeader("Location", encodedURL);
}
else if (attributeStatusCode != null) {
response.setStatus(attributeStatusCode.value());
response.setHeader("Location", encodedURL);
}
else {
// Send status code 302 by default.
response.sendRedirect(encodedURL);
}
}
else {
HttpStatus statusCode = getHttp11StatusCode(request, response, targetUrl);
response.setStatus(statusCode.value());
response.setHeader("Location", encodedURL);
}
}
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public class InternalResourceView extends AbstractUrlBasedView {
/**
* Render the internal resource given the specified model.
* This includes setting the model as request attributes.
*/
@Override
protected void renderMergedOutputModel(
Map<String, Object> model, HttpServletRequest request, HttpServletResponse response) throws Exception {

// Expose the model object as request attributes.
exposeModelAsRequestAttributes(model, request);

// Expose helpers as request attributes, if any.
exposeHelpers(request);

// Determine the path for the request dispatcher.
String dispatcherPath = prepareForRendering(request, response);

// Obtain a RequestDispatcher for the target resource (typically a JSP).
RequestDispatcher rd = getRequestDispatcher(request, dispatcherPath);
if (rd == null) {
throw new ServletException("Could not get RequestDispatcher for [" + getUrl() +
"]: Check that the corresponding file exists within your web application archive!");
}

// If already included or response already committed, perform include, else forward.
if (useInclude(request, response)) {
response.setContentType(getContentType());
if (logger.isDebugEnabled()) {
logger.debug("Including [" + getUrl() + "]");
}
rd.include(request, response);
}

else {
// Note: The forwarded resource is supposed to determine the content type itself.
if (logger.isDebugEnabled()) {
logger.debug("Forwarding to [" + getUrl() + "]");
}
rd.forward(request, response);
}
}
}

7)、CRUD-员工修改

put/delete请求的处理

由于html默认不支持put请求,因此需要

1、SpringMVC中配置HiddenHttpMethodFilter;(SpringBoot自动配置好的)
2、页面创建一个post表单
3、创建一个input项,name=”_method”;值就是我们指定的请求方式

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<input type="hidden" name="_method" value="put"/>

修改添加二合一表单

修改时在域对象中有emp对象,因此可通过emp是否为空在判断是在修改添加页面

修改页面与添加页面有三处不同:

  1. 添加put请求的表单并且添加id的表单项
  2. 将修改之前的数据进行回显(注意下拉框和日期)
  3. 修改/添加按钮
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<!--需要区分是员工修改还是添加;-->
<form th:action="@{/emp}" method="post">
<!--发送put请求修改员工数据-->
<!--
1、SpringMVC中配置HiddenHttpMethodFilter;(SpringBoot自动配置好的)
2、页面创建一个post表单
3、创建一个input项,name="_method";值就是我们指定的请求方式
-->
<input type="hidden" name="_method" value="put" th:if="${emp!=null}"/>
<input type="hidden" name="id" th:if="${emp!=null}" th:value="${emp.id}">
<div class="form-group">
<label>LastName</label>
<input name="lastName" type="text" class="form-control" placeholder="zhangsan" th:value="${emp!=null}?${emp.lastName}">
</div>
<div class="form-group">
<label>Email</label>
<input name="email" type="email" class="form-control" placeholder="zhangsan@atguigu.com" th:value="${emp!=null}?${emp.email}">
</div>
<div class="form-group">
<label>Gender</label><br/>
<div class="form-check form-check-inline">
<input class="form-check-input" type="radio" name="gender" value="1" th:checked="${emp!=null}?${emp.gender==1}">
<label class="form-check-label"></label>
</div>
<div class="form-check form-check-inline">
<input class="form-check-input" type="radio" name="gender" value="0" th:checked="${emp!=null}?${emp.gender==0}">
<label class="form-check-label"></label>
</div>
</div>
<div class="form-group">
<label>department</label>
<!--提交的是部门的id-->
<select class="form-control" name="department.id">
<option th:selected="${emp!=null}?${dept.id == emp.department.id}" th:value="${dept.id}" th:each="dept:${depts}" th:text="${dept.departmentName}">1</option>
</select>
</div>
<div class="form-group">
<label>Birth</label>
<input name="birth" type="text" class="form-control" placeholder="zhangsan" th:value="${emp!=null}?${#dates.format(emp.birth, 'yyyy-MM-dd HH:mm')}">
</div>
<button type="submit" class="btn btn-primary" th:text="${emp!=null}?'修改':'添加'">添加</button>
</form>

后台

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@GetMapping("/emp/{id}")
public String toEditPage(@PathVariable("id")Integer id,Model model) {
Employee employee = employeeDao.get(id);
Collection<Department> departments = departmentDao.getDepartments();
model.addAttribute("departments", departments);
model.addAttribute("emp", employee);
return "/emp/add";
}

@PutMapping("/emp")
public String editEmp(Employee employee) {
System.out.println(employee);
employeeDao.save(employee);
return "redirect:/emps";
}

8)、CRUD-员工删除

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<tr th:each="emp:${emps}">
<td th:text="${emp.id}"></td>
<td>[[${emp.lastName}]]</td>
<td th:text="${emp.email}"></td>
<td th:text="${emp.gender}==0?'女':'男'"></td>
<td th:text="${emp.department.departmentName}"></td>
<td th:text="${#dates.format(emp.birth, 'yyyy-MM-dd HH:mm')}"></td>
<td>
<a class="btn btn-sm btn-primary" th:href="@{/emp/}+${emp.id}">编辑</a>
<button th:attr="del_uri=@{/emp/}+${emp.id}" class="btn btn-sm btn-danger deleteBtn">删除</button>
</td>
</tr>


<script>
$(".deleteBtn").click(function(){
//删除当前员工的
$("#deleteEmpForm").attr("action",$(this).attr("del_uri")).submit();
return false;
});
</script>

7、错误处理机制

1)、SpringBoot默认的错误处理机制

默认效果:

​ 1)、浏览器,返回一个默认的错误页面

浏览器发送请求的请求头:

​ 2)、如果是其他客户端,默认响应一个json数据

原理:

​ 可以参照ErrorMvcAutoConfiguration;错误处理的自动配置;

给容器中添加了以下组件

​ 1、DefaultErrorAttributes:

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帮我们在页面共享信息;
@Override
public Map<String, Object> getErrorAttributes(RequestAttributes requestAttributes,
boolean includeStackTrace) {
Map<String, Object> errorAttributes = new LinkedHashMap<String, Object>();
errorAttributes.put("timestamp", new Date());
addStatus(errorAttributes, requestAttributes);
addErrorDetails(errorAttributes, requestAttributes, includeStackTrace);
addPath(errorAttributes, requestAttributes);
return errorAttributes;
}

​ 2、BasicErrorController:处理默认/error请求

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@Controller
@RequestMapping("${server.error.path:${error.path:/error}}")
public class BasicErrorController extends AbstractErrorController {

@RequestMapping(produces = "text/html")//产生html类型的数据;浏览器发送的请求来到这个方法处理
public ModelAndView errorHtml(HttpServletRequest request,
HttpServletResponse response) {
HttpStatus status = getStatus(request);
Map<String, Object> model = Collections.unmodifiableMap(getErrorAttributes(
request, isIncludeStackTrace(request, MediaType.TEXT_HTML)));
response.setStatus(status.value());

//去哪个页面作为错误页面;包含页面地址和页面内容
ModelAndView modelAndView = resolveErrorView(request, response, status, model);
return (modelAndView == null ? new ModelAndView("error", model) : modelAndView);
}

@RequestMapping
@ResponseBody //产生json数据,其他客户端来到这个方法处理;
public ResponseEntity<Map<String, Object>> error(HttpServletRequest request) {
Map<String, Object> body = getErrorAttributes(request,
isIncludeStackTrace(request, MediaType.ALL));
HttpStatus status = getStatus(request);
return new ResponseEntity<Map<String, Object>>(body, status);
}

​ 3、ErrorPageCustomizer:

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@Override
public void registerErrorPages(ErrorPageRegistry errorPageRegistry) {
ErrorPage errorPage = new ErrorPage(
this.dispatcherServletPath.getRelativePath(this.properties.getError().getPath()));
errorPageRegistry.addErrorPages(errorPage);
}
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public class ErrorProperties {
public String getPath() {
return this.path;
}

@Value("${error.path:/error}")
private String path = "/error";

系统出现错误以后来到error请求进行处理;(类似于web.xml注册的错误页面规则)

​ 4、DefaultErrorViewResolver:

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private static final Map<Series, String> SERIES_VIEWS;

static {
Map<Series, String> views = new EnumMap<>(Series.class);
views.put(Series.CLIENT_ERROR, "4xx");
views.put(Series.SERVER_ERROR, "5xx");
SERIES_VIEWS = Collections.unmodifiableMap(views);
}

@Override
public ModelAndView resolveErrorView(HttpServletRequest request, HttpStatus status,
Map<String, Object> model) {
ModelAndView modelAndView = resolve(String.valueOf(status), model);
if (modelAndView == null && SERIES_VIEWS.containsKey(status.series())) {
modelAndView = resolve(SERIES_VIEWS.get(status.series()), model);
}
return modelAndView;
}

private ModelAndView resolve(String viewName, Map<String, Object> model) {
//默认SpringBoot可以去找到一个页面? error/404
String errorViewName = "error/" + viewName;

//模板引擎可以解析这个页面地址就用模板引擎解析
TemplateAvailabilityProvider provider = this.templateAvailabilityProviders
.getProvider(errorViewName, this.applicationContext);
if (provider != null) {
//模板引擎可用的情况下返回到errorViewName指定的视图地址
return new ModelAndView(errorViewName, model);
}
//模板引擎不可用,就在静态资源文件夹下找errorViewName对应的页面 error/404.html
return resolveResource(errorViewName, model);
}

​ 步骤:

​ 在服务器启动时就会进入ErrorPageCustomizer注册错误页面处理路径为/error

​ 一但系统出现4xx或者5xx之类的错误;ErrorPageCustomizer就会生效(定制错误的响应规则);就会来到/error请求;就会被BasicErrorController处理;

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@RequestMapping(produces = MediaType.TEXT_HTML_VALUE)
public ModelAndView errorHtml(HttpServletRequest request, HttpServletResponse response) {
//此方法执行之前会进入DefaultErrorAttributes获取属性
HttpStatus status = getStatus(request);
Map<String, Object> model = Collections
.unmodifiableMap(getErrorAttributes(request, isIncludeStackTrace(request, MediaType.TEXT_HTML)));
response.setStatus(status.value());
//进入组件DefaultErrorViewResolver处理请求得到modelandview
ModelAndView modelAndView = resolveErrorView(request, response, status, model);
return (modelAndView != null) ? modelAndView : new ModelAndView("error", model);
}

响应页面;去哪个页面是由DefaultErrorViewResolver解析得到的;

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protected ModelAndView resolveErrorView(HttpServletRequest request,
HttpServletResponse response, HttpStatus status, Map<String, Object> model) {
//所有的ErrorViewResolver得到ModelAndView
for (ErrorViewResolver resolver : this.errorViewResolvers) {
ModelAndView modelAndView = resolver.resolveErrorView(request, status, model);
if (modelAndView != null) {
return modelAndView;
}
}
return null;
}

2)、如果定制错误响应:

1)、如何定制错误的页面;

1)、有模板引擎的情况下;error/状态码; 【将错误页面命名为 错误状态码.html 放在模板引擎文件夹里面的 error文件夹下】,发生此状态码的错误就会来到 对应的页面;

​ 我们可以使用4xx和5xx作为错误页面的文件名来匹配这种类型的所有错误,精确优先(优先寻找精确的状态码.html);

​ 页面能获取的信息;

​ timestamp:时间戳

​ status:状态码

​ error:错误提示

​ exception:异常对象

​ message:异常消息

​ errors:JSR303数据校验的错误都在这里

要想在页面获取异常对象,需要在spring配置文件中加入,默认为false

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server.error.include-exception=true

​ 2)、没有模板引擎(模板引擎找不到这个错误页面),静态资源文件夹下找;

​ 3)、以上都没有错误页面,就是默认来到SpringBoot默认的错误提示页面;

2)、如何定制错误的json数据;

​ 1)、自定义异常处理&返回定制json数据;

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@ControllerAdvice
public class MyExceptionHandler {
@ResponseBody
@ExceptionHandler(UserNotExistException.class)
public Map<String,Object> handleException(Exception e){
Map<String,Object> map = new HashMap<>();
map.put("code","user.notexist");
map.put("message",e.getMessage());
return map;
}
}

使用这种方式可以返回定制的json数据,但不能产生自适应效果,也就是浏览器和其他客户端访问时都会产生json

​ 2)、转发到/error进行自适应响应效果处理(但无法携带定制数据)

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@ExceptionHandler(UserNotExistException.class)
public String handleException(Exception e, HttpServletRequest request){
Map<String,Object> map = new HashMap<>();
//传入我们自己的错误状态码 4xx 5xx,否则就不会进入定制错误页面的解析流程
/**
* Integer statusCode = (Integer) request
.getAttribute("javax.servlet.error.status_code");
*/
request.setAttribute("javax.servlet.error.status_code",500);
map.put("code","user.notexist");
map.put("message",e.getMessage());
//将信息放入request域中,以便之后取出
request.setAttribute("ext",map);
//转发到/error
return "forward:/error";
}

必须要在request域内设置javax.servlet.error.status_code属性,否则状态码默认设置为200,因此无法找到正确的错误页面

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protected HttpStatus getStatus(HttpServletRequest request) {
Integer statusCode = (Integer) request.getAttribute("javax.servlet.error.status_code");
if (statusCode == null) {
return HttpStatus.INTERNAL_SERVER_ERROR;
}
try {
return HttpStatus.valueOf(statusCode);
}
catch (Exception ex) {
return HttpStatus.INTERNAL_SERVER_ERROR;
}
}

3)、将我们的定制数据携带出去;

出现错误以后,会来到/error请求,会被BasicErrorController处理,响应出去可以获取的数据是由getErrorAttributes得到的(是AbstractErrorController(ErrorController)规定的方法);

​ 1、完全来编写一个ErrorController的实现类【或者是编写AbstractErrorController的子类】,放在容器中;

​ 2、页面上能用的数据,或者是json返回能用的数据都是通过errorAttributes.getErrorAttributes得到;

​ 容器中DefaultErrorAttributes.getErrorAttributes();默认进行数据处理的;

自定义ErrorAttributes

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//给容器中加入我们自己定义的ErrorAttributes
@Component
public class MyErrorAttributes extends DefaultErrorAttributes {

@Override
public Map<String, Object> getErrorAttributes(RequestAttributes requestAttributes, boolean includeStackTrace) {
Map<String, Object> map = super.getErrorAttributes(requestAttributes, includeStackTrace);
//将之前request域中的信息取出
Map<String,Object> ext = (Map<String, Object>) webRequest.getAttribute("ext", 0);
map.put("ext", ext);
map.put("company","atguigu");
return map;
}
}

最终的效果:响应是自适应的,可以通过定制ErrorAttributes改变需要返回的内容,

8、配置嵌入式Servlet容器

SpringBoot默认使用Tomcat作为嵌入式的Servlet容器;

问题?

1)、如何定制和修改Servlet容器的相关配置;

1、修改和server有关的配置(ServerProperties);

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server.port=8081
server.context-path=/crud

server.tomcat.uri-encoding=UTF-8

//通用的Servlet容器设置
server.xxx
//Tomcat的设置
server.tomcat.xxx

ServerProperties的原理

ServerProperties类中有许多属性都可以使用配置文件配置,@ConfigurationProperties注解使得将配置文件转化为Javabean对象,配置文件中前缀为server

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@ConfigurationProperties(prefix = "server", ignoreUnknownFields = true)
public class ServerProperties {

private Integer port;

private final Servlet servlet = new Servlet();

private final Tomcat tomcat = new Tomcat();
...

在服务器启动时容器中导入了许多自动配置类,其中ServletWebServerFactoryAutoConfiguration类上@EnableConfigurationProperties(ServerProperties.class)保证了ServerProperties可以的@ConfigurationProperties可以起作用

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@Configuration(proxyBeanMethods = false)
@AutoConfigureOrder(Ordered.HIGHEST_PRECEDENCE)
@ConditionalOnClass(ServletRequest.class)
@ConditionalOnWebApplication(type = Type.SERVLET)
@EnableConfigurationProperties(ServerProperties.class)
@Import({ ServletWebServerFactoryAutoConfiguration.BeanPostProcessorsRegistrar.class,
ServletWebServerFactoryConfiguration.EmbeddedTomcat.class,
ServletWebServerFactoryConfiguration.EmbeddedJetty.class,
ServletWebServerFactoryConfiguration.EmbeddedUndertow.class })
public class ServletWebServerFactoryAutoConfiguration {

2、编写一个WebServerFactoryCustomizer:嵌入式的Servlet容器的定制器;来修改Servlet容器的配置

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@Bean  //一定要将这个定制器加入到容器中
public WebServerFactoryCustomizer<ConfigurableServletWebServerFactory> embeddedServletContainerCustomizer(){
return new WebServerFactoryCustomizer<ConfigurableServletWebServerFactory>() {
@Override
public void customize(ConfigurableServletWebServerFactory factory) {
factory.setPort(9000);
factory.setContextPath("/cccc");
}

};
}

2)、注册Servlet三大组件【Servlet、Filter、Listener】

由于SpringBoot默认是以jar包的方式启动嵌入式的Servlet容器来启动SpringBoot的web应用,没有web.xml文件。

注册三大组件用以下方式

ServletRegistrationBean

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//注册三大组件
@Bean
public ServletRegistrationBean myServlet(){
ServletRegistrationBean registrationBean = new ServletRegistrationBean(new MyServlet(),"/myServlet");
return registrationBean;
}

FilterRegistrationBean

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@Bean
public FilterRegistrationBean myFilter(){
FilterRegistrationBean registrationBean = new FilterRegistrationBean();
registrationBean.setFilter(new MyFilter());
registrationBean.setUrlPatterns(Arrays.asList("/hello","/myServlet"));
return registrationBean;
}

ServletListenerRegistrationBean

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@Bean
public ServletListenerRegistrationBean myListener(){
ServletListenerRegistrationBean<MyListener> registrationBean = new ServletListenerRegistrationBean<>(new MyListener());
return registrationBean;
}

SpringBoot帮我们自动SpringMVC的时候,自动的注册SpringMVC的前端控制器;DIspatcherServlet;

DispatcherServletAutoConfiguration中:

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@Bean(name = DEFAULT_DISPATCHER_SERVLET_REGISTRATION_BEAN_NAME)
@ConditionalOnBean(value = DispatcherServlet.class, name = DEFAULT_DISPATCHER_SERVLET_BEAN_NAME)
public ServletRegistrationBean dispatcherServletRegistration(
DispatcherServlet dispatcherServlet) {
ServletRegistrationBean registration = new ServletRegistrationBean(
dispatcherServlet, this.serverProperties.getServletMapping());
//默认拦截: / 所有请求;包静态资源,但是不拦截jsp请求; /*会拦截jsp
//可以通过server.servletPath来修改SpringMVC前端控制器默认拦截的请求路径

registration.setName(DEFAULT_DISPATCHER_SERVLET_BEAN_NAME);
registration.setLoadOnStartup(
this.webMvcProperties.getServlet().getLoadOnStartup());
if (this.multipartConfig != null) {
registration.setMultipartConfig(this.multipartConfig);
}
return registration;
}

2)、SpringBoot能不能支持其他的Servlet容器;

要想使用其他的容器,要先排除tomcat依赖

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<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<exclusions>
<exclusion>
<artifactId>spring-boot-starter-tomcat</artifactId>
<groupId>org.springframework.boot</groupId>
</exclusion>
</exclusions>
</dependency>

3)、替换为其他嵌入式Servlet容器

默认支持:

Tomcat(默认使用)

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<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
引入web模块默认就是使用嵌入式的Tomcat作为Servlet容器;
</dependency>

Jetty

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<!-- 引入web模块 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<exclusions>
<exclusion>
<artifactId>spring-boot-starter-tomcat</artifactId>
<groupId>org.springframework.boot</groupId>
</exclusion>
</exclusions>
</dependency>

<!--引入其他的Servlet容器-->
<dependency>
<artifactId>spring-boot-starter-jetty</artifactId>
<groupId>org.springframework.boot</groupId>
</dependency>

Undertow

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<!-- 引入web模块 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<exclusions>
<exclusion>
<artifactId>spring-boot-starter-tomcat</artifactId>
<groupId>org.springframework.boot</groupId>
</exclusion>
</exclusions>
</dependency>

<!--引入其他的Servlet容器-->
<dependency>
<artifactId>spring-boot-starter-undertow</artifactId>
<groupId>org.springframework.boot</groupId>
</dependency>

4)、嵌入式Servlet容器自动配置原理;

1. ServletWebServerFactoryAutoConfiguration:嵌入式的Servlet容器自动配置类

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@Configuration(proxyBeanMethods = false)
@AutoConfigureOrder(Ordered.HIGHEST_PRECEDENCE)
@ConditionalOnClass(ServletRequest.class)
@ConditionalOnWebApplication(type = Type.SERVLET)
@EnableConfigurationProperties(ServerProperties.class)
@Import({ ServletWebServerFactoryAutoConfiguration.BeanPostProcessorsRegistrar.class,
ServletWebServerFactoryConfiguration.EmbeddedTomcat.class,
ServletWebServerFactoryConfiguration.EmbeddedJetty.class,
ServletWebServerFactoryConfiguration.EmbeddedUndertow.class })
public class ServletWebServerFactoryAutoConfiguration {

该类导入了BeanPostProcessorsRegistrar和ServletWebServerFactoryConfiguration类中的内部类EmbeddedTomcatEmbeddedJettyEmbeddedUndertow

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@Configuration(proxyBeanMethods = false)
class ServletWebServerFactoryConfiguration {

@Configuration(proxyBeanMethods = false)
@ConditionalOnClass({ Servlet.class, Tomcat.class, UpgradeProtocol.class })
@ConditionalOnMissingBean(value = ServletWebServerFactory.class, search = SearchStrategy.CURRENT)
static class EmbeddedTomcat {

@Bean
TomcatServletWebServerFactory tomcatServletWebServerFactory(
ObjectProvider<TomcatConnectorCustomizer> connectorCustomizers,
ObjectProvider<TomcatContextCustomizer> contextCustomizers,
ObjectProvider<TomcatProtocolHandlerCustomizer<?>> protocolHandlerCustomizers) {
TomcatServletWebServerFactory factory = new TomcatServletWebServerFactory();
factory.getTomcatConnectorCustomizers()
.addAll(connectorCustomizers.orderedStream().collect(Collectors.toList()));
factory.getTomcatContextCustomizers()
.addAll(contextCustomizers.orderedStream().collect(Collectors.toList()));
factory.getTomcatProtocolHandlerCustomizers()
.addAll(protocolHandlerCustomizers.orderedStream().collect(Collectors.toList()));
return factory;
}

}

/**
* Nested configuration if Jetty is being used.
*/
@Configuration(proxyBeanMethods = false)
@ConditionalOnClass({ Servlet.class, Server.class, Loader.class, WebAppContext.class })
@ConditionalOnMissingBean(value = ServletWebServerFactory.class, search = SearchStrategy.CURRENT)
static class EmbeddedJetty {

@Bean
JettyServletWebServerFactory JettyServletWebServerFactory(
ObjectProvider<JettyServerCustomizer> serverCustomizers) {
JettyServletWebServerFactory factory = new JettyServletWebServerFactory();
factory.getServerCustomizers().addAll(serverCustomizers.orderedStream().collect(Collectors.toList()));
return factory;
}

}

/**
* Nested configuration if Undertow is being used.
*/
@Configuration(proxyBeanMethods = false)
@ConditionalOnClass({ Servlet.class, Undertow.class, SslClientAuthMode.class })
@ConditionalOnMissingBean(value = ServletWebServerFactory.class, search = SearchStrategy.CURRENT)
static class EmbeddedUndertow {

@Bean
UndertowServletWebServerFactory undertowServletWebServerFactory(
ObjectProvider<UndertowDeploymentInfoCustomizer> deploymentInfoCustomizers,
ObjectProvider<UndertowBuilderCustomizer> builderCustomizers) {
UndertowServletWebServerFactory factory = new UndertowServletWebServerFactory();
factory.getDeploymentInfoCustomizers()
.addAll(deploymentInfoCustomizers.orderedStream().collect(Collectors.toList()));
factory.getBuilderCustomizers().addAll(builderCustomizers.orderedStream().collect(Collectors.toList()));
return factory;
}

}

}

ServletWebServerFactoryConfiguration会根据容器中@ConditionalOnClass判断使用哪个嵌入式容器,然后将其工厂容器化

继承关系

2. 嵌入式Tomcat的创建与启动

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@Configuration(proxyBeanMethods = false)
@ConditionalOnClass({ Servlet.class, Tomcat.class, UpgradeProtocol.class })
@ConditionalOnMissingBean(value = ServletWebServerFactory.class, search = SearchStrategy.CURRENT)
static class EmbeddedTomcat {
@Bean
TomcatServletWebServerFactory tomcatServletWebServerFactory(
ObjectProvider<TomcatConnectorCustomizer> connectorCustomizers,
ObjectProvider<TomcatContextCustomizer> contextCustomizers,
ObjectProvider<TomcatProtocolHandlerCustomizer<?>> protocolHandlerCustomizers) {
TomcatServletWebServerFactory factory = new TomcatServletWebServerFactory();
factory.getTomcatConnectorCustomizers()
.addAll(connectorCustomizers.orderedStream().collect(Collectors.toList()));
factory.getTomcatContextCustomizers()
.addAll(contextCustomizers.orderedStream().collect(Collectors.toList()));
factory.getTomcatProtocolHandlerCustomizers()
.addAll(protocolHandlerCustomizers.orderedStream().collect(Collectors.toList()));
return factory;
}

EmbeddedTomcat将TomcatServletWebServerFactory做了一些设置,并导入容器

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public class TomcatServletWebServerFactory extends AbstractServletWebServerFactory
implements ConfigurableTomcatWebServerFactory, ResourceLoaderAware {
@Override
public WebServer getWebServer(ServletContextInitializer... initializers) {
if (this.disableMBeanRegistry) {
Registry.disableRegistry();
}
//创建Tomcat
Tomcat tomcat = new Tomcat();

//配置Tomcat的基本环节
File baseDir = (this.baseDirectory != null) ? this.baseDirectory : createTempDir("tomcat");
tomcat.setBaseDir(baseDir.getAbsolutePath());
Connector connector = new Connector(this.protocol);
connector.setThrowOnFailure(true);
tomcat.getService().addConnector(connector);
customizeConnector(connector);
tomcat.setConnector(connector);
tomcat.getHost().setAutoDeploy(false);
configureEngine(tomcat.getEngine());
for (Connector additionalConnector : this.additionalTomcatConnectors) {
tomcat.getService().addConnector(additionalConnector);
}
prepareContext(tomcat.getHost(), initializers);

//将配置好的Tomcat传入进去,返回一个TomcatWebServer;并且启动Tomcat服务器
return getTomcatWebServer(tomcat);
}

protected TomcatWebServer getTomcatWebServer(Tomcat tomcat) {
//端口号>0就自动开始
return new TomcatWebServer(tomcat, getPort() >= 0);
}

可以看到创建Tomcat的最后是调用了getTomcatWebServe( ) 方法,而方法调用了TomcatWebServer的构造器,因此进入TomcatWebServer中

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public class TomcatWebServer implements WebServer {
public TomcatWebServer(Tomcat tomcat, boolean autoStart) {
Assert.notNull(tomcat, "Tomcat Server must not be null");
this.tomcat = tomcat;
this.autoStart = autoStart;
initialize();
}

private void initialize() throws WebServerException {
logger.info("Tomcat initialized with port(s): " + getPortsDescription(false));
synchronized (this.monitor) {
try {
addInstanceIdToEngineName();

Context context = findContext();
context.addLifecycleListener((event) -> {
if (context.equals(event.getSource()) && Lifecycle.START_EVENT.equals(event.getType())) {
removeServiceConnectors();
}
});

//启动Tomcat
this.tomcat.start();

rethrowDeferredStartupExceptions();

try {
ContextBindings.bindClassLoader(context, context.getNamingToken(), getClass().getClassLoader());
}
catch (NamingException ex) {

}
startDaemonAwaitThread();
}
catch (Exception ex) {
stopSilently();
destroySilently();
//不能启动则抛出异常
throw new WebServerException("Unable to start embedded Tomcat", ex);
}
}
}

在TomcatWebServer类中启动嵌入式Tomcat,如果不能启动则抛出异常

3. 我们对嵌入式容器的配置修改是怎么生效

ServletWebServerFactoryAutoConfiguration还导入了其内部类BeanPostProcessorsRegistrar类

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public static class BeanPostProcessorsRegistrar implements ImportBeanDefinitionRegistrar, BeanFactoryAware {
@Override
public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata,
BeanDefinitionRegistry registry) {
if (this.beanFactory == null) {
return;
}
//如果容器中没有则注册WebServerFactoryCustomizerBeanPostProcessor类
registerSyntheticBeanIfMissing(registry, "webServerFactoryCustomizerBeanPostProcessor",
WebServerFactoryCustomizerBeanPostProcessor.class);
registerSyntheticBeanIfMissing(registry, "errorPageRegistrarBeanPostProcessor",
ErrorPageRegistrarBeanPostProcessor.class);
}

BeanPostProcessorsRegistrar注册了WebServerFactoryCustomizerBeanPostProcessor类

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public class WebServerFactoryCustomizerBeanPostProcessor implements BeanPostProcessor, BeanFactoryAware {
@Override
public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
//如果当前初始化的为WebServerFactory类型的组件,则开启后处理
if (bean instanceof WebServerFactory) {
postProcessBeforeInitialization((WebServerFactory) bean);
}
return bean;
}


//在WebServerFactory初始化之前调用WebServerFactoryCustomizer的所有customize()方法
private void postProcessBeforeInitialization(WebServerFactory webServerFactory) {
LambdaSafe.callbacks(WebServerFactoryCustomizer.class, getCustomizers(), webServerFactory)
.withLogger(WebServerFactoryCustomizerBeanPostProcessor.class)
.invoke((customizer) -> customizer.customize(webServerFactory));
}

WebServerFactoryCustomizerBeanPostProcessor在WebServerFactory初始化前回调了WebServerFactoryCustomizer的方法,而该方法就是我们的定制方法,=,下面是我们自己的配置类中定制代码

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@Configuration
public class MyMvcConfig implements WebMvcConfigurer {
@Bean
public WebServerFactoryCustomizer<ConfigurableServletWebServerFactory> webServerFactoryCustomizer(){
return new WebServerFactoryCustomizer<ConfigurableServletWebServerFactory>() {
@Override
public void customize(ConfigurableServletWebServerFactory factory) {
factory.setPort(9000);
factory.setContextPath("/cccc");
}

};
}

步骤:

1)、SpringBoot根据导入的依赖情况,给容器中添加相应的ServletWebServerFactory

2)、容器中某个组件要创建对象就会惊动后置处理器WebServerFactoryCustomizerBeanPostProcessor;

只要是嵌入式的Servlet容器工厂,后置处理器就工作;

3)、后置处理器,从容器中获取所有的WebServerFactoryCustomizer,调用定制器的定制方法

==嵌入式Servlet容器启动原理==

什么时候创建嵌入式的Servlet容器工厂?什么时候获取嵌入式的Servlet容器并启动Tomcat;

获取嵌入式的Servlet容器工厂:

1)、SpringBoot应用启动运行run方法

2)、refreshContext(context);SpringBoot刷新IOC容器【创建IOC容器对象,并初始化容器,创建容器中的每一个组件】;并根据web应用的类型创建对应的IOC容器对象(如AnnotationConfigServletWebServerApplicationContext)

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public class SpringApplication {
public ConfigurableApplicationContext run(String... args) {
...
//创建IOC容器
context = createApplicationContext();
exceptionReporters = getSpringFactoriesInstances(SpringBootExceptionReporter.class,
new Class[] { ConfigurableApplicationContext.class }, context);
prepareContext(context, environment, listeners, applicationArguments, printedBanner);
//刷新IOC容器
refreshContext(context);
afterRefresh(context, applicationArguments);
...
}

protected ConfigurableApplicationContext createApplicationContext() {
Class<?> contextClass = this.applicationContextClass;
//如果不是普通应用则创建web应用容器
if (contextClass == null) {
try {
//根据web应用类型创建对应IOC容器
switch (this.webApplicationType) {
case SERVLET:
//AnnotationConfigServletWebServerApplicationContext
contextClass = Class.forName(DEFAULT_SERVLET_WEB_CONTEXT_CLASS);
break;
case REACTIVE:
contextClass = Class.forName(DEFAULT_REACTIVE_WEB_CONTEXT_CLASS);
break;
default:
contextClass = Class.forName(DEFAULT_CONTEXT_CLASS);
}
}
catch (ClassNotFoundException ex) {
throw new IllegalStateException(
"Unable create a default ApplicationContext, please specify an ApplicationContextClass", ex);
}
}
return (ConfigurableApplicationContext) BeanUtils.instantiateClass(contextClass);
}

3)、refresh(context);刷新刚才创建好的ioc容器;

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public void refresh() throws BeansException, IllegalStateException {
synchronized (this.startupShutdownMonitor) {
// Prepare this context for refreshing.
prepareRefresh();

// Tell the subclass to refresh the internal bean factory.
ConfigurableListableBeanFactory beanFactory = obtainFreshBeanFactory();

// Prepare the bean factory for use in this context.
prepareBeanFactory(beanFactory);

try {
// Allows post-processing of the bean factory in context subclasses.
postProcessBeanFactory(beanFactory);

// Invoke factory processors registered as beans in the context.
invokeBeanFactoryPostProcessors(beanFactory);

// Register bean processors that intercept bean creation.
registerBeanPostProcessors(beanFactory);

// Initialize message source for this context.
initMessageSource();

// Initialize event multicaster for this context.
initApplicationEventMulticaster();

// Initialize other special beans in specific context subclasses.
onRefresh();

// Check for listener beans and register them.
registerListeners();

// Instantiate all remaining (non-lazy-init) singletons.
finishBeanFactoryInitialization(beanFactory);

// Last step: publish corresponding event.
finishRefresh();
}

catch (BeansException ex) {
if (logger.isWarnEnabled()) {
logger.warn("Exception encountered during context initialization - " +
"cancelling refresh attempt: " + ex);
}

// Destroy already created singletons to avoid dangling resources.
destroyBeans();

// Reset 'active' flag.
cancelRefresh(ex);

// Propagate exception to caller.
throw ex;
}

finally {
// Reset common introspection caches in Spring's core, since we
// might not ever need metadata for singleton beans anymore...
resetCommonCaches();
}
}
}

4)、 onRefresh(); web的ioc容器重写了onRefresh方法,在此方法中调用getWebServerFactory(),根据环境创建工厂,因为此时为tomcat环境,因此创建了TomcatServletWebServerFactory。

5)、ServletWebServerFactory的创建触发了后置处理器,获取所有的定制器来先定制Servlet容器的相关配置;

6)、此时ServletWebServerFactory实际引用了TomcatServletWebServerFactory,因此调用了TomcatServletWebServerFactory的getWebServer( )方法,在该方法中tomcat被创建并启动。

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public class ServletWebServerApplicationContext extends GenericWebApplicationContext
implements ConfigurableWebServerApplicationContext {
@Override
protected void onRefresh() {
super.onRefresh();
try {
createWebServer();
}
catch (Throwable ex) {
throw new ApplicationContextException("Unable to start web server", ex);
}
}

private void createWebServer() {
WebServer webServer = this.webServer;
ServletContext servletContext = getServletContext();
if (webServer == null && servletContext == null) {
//由于此时为tomcat环境,因此ServletWebServerFactory实际上就是TomcatServletWebServerFactory
ServletWebServerFactory factory = getWebServerFactory();
//调用TomcatServletWebServerFactory的getWebServer()方法
this.webServer = factory.getWebServer(getSelfInitializer());
}
else if (servletContext != null) {
try {
getSelfInitializer().onStartup(servletContext);
}
catch (ServletException ex) {
throw new ApplicationContextException("Cannot initialize servlet context", ex);
}
}
initPropertySources();
}
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public class TomcatServletWebServerFactory extends AbstractServletWebServerFactory
implements ConfigurableTomcatWebServerFactory, ResourceLoaderAware {
@Override
public WebServer getWebServer(ServletContextInitializer... initializers) {
if (this.disableMBeanRegistry) {
Registry.disableRegistry();
}
//创建Tomcat并启动
Tomcat tomcat = new Tomcat();
File baseDir = (this.baseDirectory != null) ? this.baseDirectory : createTempDir("tomcat");
tomcat.setBaseDir(baseDir.getAbsolutePath());
Connector connector = new Connector(this.protocol);
connector.setThrowOnFailure(true);
tomcat.getService().addConnector(connector);
customizeConnector(connector);
tomcat.setConnector(connector);
tomcat.getHost().setAutoDeploy(false);
configureEngine(tomcat.getEngine());
for (Connector additionalConnector : this.additionalTomcatConnectors) {
tomcat.getService().addConnector(additionalConnector);
}
prepareContext(tomcat.getHost(), initializers);
return getTomcatWebServer(tomcat);
}

9、使用外置的Servlet容器

嵌入式Servlet容器:应用打成可执行的jar

​ 优点:简单、便携;

​ 缺点:默认不支持JSP、优化定制比较复杂(使用定制器【ServerProperties、自定义EmbeddedServletContainerCustomizer】,自己编写嵌入式Servlet容器的创建工厂【EmbeddedServletContainerFactory】);

外置的Servlet容器:外面安装Tomcat—应用war包的方式打包;

步骤

1)、必须创建一个war项目;(利用idea创建好目录结构)

2)、将嵌入式的Tomcat指定为provided;

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<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-tomcat</artifactId>
<scope>provided</scope>
</dependency>

3)、必须编写一个SpringBootServletInitializer的子类,并调用configure方法

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public class ServletInitializer extends SpringBootServletInitializer {

@Override
protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
//传入SpringBoot应用的主程序
return application.sources(SpringBoot04WebJspApplication.class);
}

}

4)、启动服务器就可以使用;

原理

jar包:执行SpringBoot主类的main方法,启动ioc容器,创建嵌入式的Servlet容器;

war包:启动服务器,服务器启动SpringBoot应用【SpringBootServletInitializer】,启动ioc容器;

servlet3.0(Spring注解版):

8.2.4 Shared libraries / runtimes pluggability:

规则:

​ 1)、服务器启动(web应用启动)会创建当前web应用里面每一个jar包里面ServletContainerInitializer实例:

​ 2)、ServletContainerInitializer的实现放在jar包的META-INF/services文件夹下,有一个名为javax.servlet.ServletContainerInitializer的文件,内容就是ServletContainerInitializer的实现类的全类名

​ 3)、还可以使用@HandlesTypes,在应用启动的时候加载我们感兴趣的类;

流程:

1)、启动Tomcat

2)、org\springframework\spring-web\4.3.14.RELEASE\spring-web-4.3.14.RELEASE.jar!\META-INF\services\javax.servlet.ServletContainerInitializer:

Spring的web模块里面有这个文件:org.springframework.web.SpringServletContainerInitializer

3)、SpringServletContainerInitializer将@HandlesTypes(WebApplicationInitializer.class)标注的所有这个类型的类都传入到onStartup方法的Set<Class<?>>;为这些WebApplicationInitializer类型的类创建实例;

4)、每一个WebApplicationInitializer都调用自己的onStartup;

5)、相当于我们的SpringBootServletInitializer的类会被创建对象,并执行onStartup方法

6)、SpringBootServletInitializer实例执行onStartup的时候会createRootApplicationContext;创建容器

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protected WebApplicationContext createRootApplicationContext(
ServletContext servletContext) {
//1、创建SpringApplicationBuilder
SpringApplicationBuilder builder = createSpringApplicationBuilder();
StandardServletEnvironment environment = new StandardServletEnvironment();
environment.initPropertySources(servletContext, null);
builder.environment(environment);
builder.main(getClass());
ApplicationContext parent = getExistingRootWebApplicationContext(servletContext);
if (parent != null) {
this.logger.info("Root context already created (using as parent).");
servletContext.setAttribute(
WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE, null);
builder.initializers(new ParentContextApplicationContextInitializer(parent));
}
builder.initializers(
new ServletContextApplicationContextInitializer(servletContext));
builder.contextClass(AnnotationConfigEmbeddedWebApplicationContext.class);

//调用configure方法,子类重写了这个方法,将SpringBoot的主程序类传入了进来
builder = configure(builder);

//使用builder创建一个Spring应用
SpringApplication application = builder.build();
if (application.getSources().isEmpty() && AnnotationUtils
.findAnnotation(getClass(), Configuration.class) != null) {
application.getSources().add(getClass());
}
Assert.state(!application.getSources().isEmpty(),
"No SpringApplication sources have been defined. Either override the "
+ "configure method or add an @Configuration annotation");
// Ensure error pages are registered
if (this.registerErrorPageFilter) {
application.getSources().add(ErrorPageFilterConfiguration.class);
}
//启动Spring应用
return run(application);
}

7)、Spring的应用就启动并且创建IOC容器

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public ConfigurableApplicationContext run(String... args) {
StopWatch stopWatch = new StopWatch();
stopWatch.start();
ConfigurableApplicationContext context = null;
FailureAnalyzers analyzers = null;
configureHeadlessProperty();
SpringApplicationRunListeners listeners = getRunListeners(args);
listeners.starting();
try {
ApplicationArguments applicationArguments = new DefaultApplicationArguments(
args);
ConfigurableEnvironment environment = prepareEnvironment(listeners,
applicationArguments);
Banner printedBanner = printBanner(environment);
context = createApplicationContext();
analyzers = new FailureAnalyzers(context);
prepareContext(context, environment, listeners, applicationArguments,
printedBanner);

//刷新IOC容器
refreshContext(context);
afterRefresh(context, applicationArguments);
listeners.finished(context, null);
stopWatch.stop();
if (this.logStartupInfo) {
new StartupInfoLogger(this.mainApplicationClass)
.logStarted(getApplicationLog(), stopWatch);
}
return context;
}
catch (Throwable ex) {
handleRunFailure(context, listeners, analyzers, ex);
throw new IllegalStateException(ex);
}
}

==启动Servlet容器,再启动SpringBoot应用==

五、Docker

1、简介

Docker是一个开源的应用容器引擎;是一个轻量级容器技术;

Docker支持将软件编译成一个镜像;然后在镜像中各种软件做好配置,将镜像发布出去,其他使用者可以直接使用这个镜像;

运行中的这个镜像称为容器,容器启动是非常快速的。

2、核心概念

docker主机(Host):安装了Docker程序的机器(Docker直接安装在操作系统之上);

docker客户端(Client):连接docker主机进行操作;

docker仓库(Registry):用来保存各种打包好的软件镜像;

docker镜像(Images):软件打包好的镜像;放在docker仓库中;

docker容器(Container):镜像启动后的实例称为一个容器;容器是独立运行的一个或一组应用

使用Docker的步骤:

1)、安装Docker

2)、去Docker仓库找到这个软件对应的镜像;

3)、使用Docker运行这个镜像,这个镜像就会生成一个Docker容器;

4)、对容器的启动停止就是对软件的启动停止;

3、安装Docker

1)、安装linux虚拟机

​ 1)、VMWare、VirtualBox(安装);

​ 2)、导入虚拟机文件centos7-atguigu.ova;

​ 3)、双击启动linux虚拟机;使用 root/ 123456登陆

​ 4)、使用客户端连接linux服务器进行命令操作;

​ 5)、设置虚拟机网络;

​ 桥接网络===选好网卡====接入网线;

​ 6)、设置好网络以后使用命令重启虚拟机的网络

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service network restart

​ 7)、查看linux的ip地址

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ip addr

​ 8)、使用客户端连接linux;

2)、在linux虚拟机上安装docker

步骤:

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1、检查内核版本,必须是3.10及以上
uname -r
2、安装docker
yum install docker
3、输入y确认安装
4、启动docker
[root@localhost ~]# systemctl start docker
[root@localhost ~]# docker -v
Docker version 1.12.6, build 3e8e77d/1.12.6
5、开机启动docker
[root@localhost ~]# systemctl enable docker
Created symlink from /etc/systemd/system/multi-user.target.wants/docker.service to /usr/lib/systemd/system/docker.service.
6、停止docker
systemctl stop docker

4、Docker常用命令&操作

1)、镜像操作

操作 命令 说明
检索 docker search 关键字 eg:docker search redis 我们经常去docker hub上检索镜像的详细信息,如镜像的TAG。
拉取 docker pull 镜像名:tag :tag是可选的,tag表示标签,多为软件的版本,默认是latest
列表 docker images 查看所有本地镜像
删除 docker rmi image-id 删除指定的本地镜像

https://hub.docker.com/

2)、容器操作

软件镜像(QQ安装程序)—-运行镜像—-产生一个容器(正在运行的软件,运行的QQ);

步骤:

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1、搜索镜像
docker search tomcat

2、拉取镜像
docker pull tomcat

3、根据镜像启动容器
docker run --name mytomcat -d tomcat:latest

4、查看运行中的容器
docker ps

5、 停止运行中的容器
docker stop 容器的id

6、查看所有的容器
docker ps -a

7、启动容器
docker start 容器id
-d:后台运行
-p:将主机的端口映射到容器的一个端口 主机端口:容器内部的端口
-e:设置环境变量
--name:设置容器名
---restart:重启规则
--restart=unless-stopped 表示docker启动时该容器自启

启动一个做了端口映射的tomcat,设置其root密码为123456,且docker启动自启
docker run --name mysql01 -e MYSQL_ROOT_PASSWORD=123456 -p 3306:3306 -d --restart=unless-stopped 413be204e9c3


8、删除一个容器
docker rm 容器id


10、为了演示简单关闭了linux的防火墙
service firewalld status ;查看防火墙状态
service firewalld stop:关闭防火墙

11、查看容器的日志
docker logs container-name/container-id

12、进入容器内
docker exec -ti 容器ID /bin/bash

更多命令参看
https://docs.docker.com/engine/reference/commandline/docker/
可以参考每一个镜像的文档

tomcat启动后访问主页后出现404

解决方案

3)、安装MySQL示例

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docker pull mysql

错误的启动

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[root@localhost ~]# docker run --name mysql01 -d mysql
42f09819908bb72dd99ae19e792e0a5d03c48638421fa64cce5f8ba0f40f5846

mysql退出了
[root@localhost ~]# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
42f09819908b mysql "docker-entrypoint.sh" 34 seconds ago Exited (1) 33 seconds ago mysql01
538bde63e500 tomcat "catalina.sh run" About an hour ago Exited (143) About an hour ago compassionate_
goldstine
c4f1ac60b3fc tomcat "catalina.sh run" About an hour ago Exited (143) About an hour ago lonely_fermi
81ec743a5271 tomcat "catalina.sh run" About an hour ago Exited (143) About an hour ago sick_ramanujan


//错误日志
//要指定mysql密码
[root@localhost ~]# docker logs 42f09819908b
error: database is uninitialized and password option is not specified
You need to specify one of MYSQL_ROOT_PASSWORD, MYSQL_ALLOW_EMPTY_PASSWORD and MYSQL_RANDOM_ROOT_PASSWORD;这个三个参数必须指定一个

正确的启动

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[root@localhost ~]# docker run --name mysql01 -e MYSQL_ROOT_PASSWORD=123456 -d mysql
b874c56bec49fb43024b3805ab51e9097da779f2f572c22c695305dedd684c5f
[root@localhost ~]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
b874c56bec49 mysql "docker-entrypoint.sh" 4 seconds ago Up 3 seconds 3306/tcp mysql01

做了端口映射

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[root@localhost ~]# docker run -p 3306:3306 --name mysql02 -e MYSQL_ROOT_PASSWORD=123456 -d mysql
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[root@localhost ~]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
ad10e4bc5c6a mysql "docker-entrypoint.sh" 4 seconds ago Up 2 seconds 0.0.0.0:3306->3306/tcp mysql02

几个其他的高级操作

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docker run --name mysql03 -v /conf/mysql:/etc/mysql/conf.d -e MYSQL_ROOT_PASSWORD=my-secret-pw -d mysql:tag
把主机的/conf/mysql文件夹挂载到 mysqldocker容器的/etc/mysql/conf.d文件夹里面
改mysql的配置文件就只需要把mysql配置文件放在自定义的文件夹下(/conf/mysql)

docker run --name some-mysql -e MYSQL_ROOT_PASSWORD=my-secret-pw -d mysql:tag --character-set-server=utf8mb4 --collation-server=utf8mb4_unicode_ci
指定mysql的一些配置参数

如何使用官方镜像

Docker 中国官方镜像加速可通过 registry.docker-cn.com 访问。目前该镜像库只包含流行的公有镜像,而私有镜像仍需要从美国镜像库中拉取。

可以使用以下命令直接从该镜像加速地址进行拉取。

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docker pull registry.docker-cn.com/myname/myrepo:mytag

示例如下:

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注:除非您修改了Docker守护进程的–registry-mirror参数,否则您将需要完整地指定官方镜像的名称。例如,library/ubuntu、library/redis、library/nginx。

给Docker守护进程配置加速器

通过配置文件启动Docker,修改/etc/docker/daemon.json 文件并添加上 registry-mirrors 键值。

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sudo vim /etc/docker/daemon.json
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{
"registry-mirrors": ["https://registry.docker-cn.com"]
}

也可选用网易的镜像地址:http://hub-mirror.c.163.com
{
“registry-mirrors”: [“http://hub-mirror.c.163.com"]
}

修改保存后,重启 Docker 以使配置生效。

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sudo service docker restart

六、SpringBoot与数据访问

1、JDBC

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<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
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spring:
datasource:
username: root
password: 123
# 在url之后要加上时区信息,否则会报错(mysql版本高对安全校验的提高)
url: jdbc:mysql://127.0.0.1:3306/springboot?serverTimezone=Asia/Shanghai
driver-class-name: com.mysql.jdbc.Driver

效果:

​ 2.2.5版本默认是用com.zaxxer.hikari.HikariDataSource作为数据源;

​ 数据源的相关配置都在DataSourceProperties里面;

自动配置原理:

org.springframework.boot.autoconfigure.jdbc:

1、参考DataSourceConfiguration,根据配置创建数据源,默认使用Tomcat连接池;可以使用spring.datasource.type指定自定义的数据源类型;

2、SpringBoot默认可以支持;

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org.apache.tomcat.jdbc.pool.DataSource、HikariDataSource、BasicDataSource、

3、自定义数据源类型

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/**
* Generic DataSource configuration.
*/
@Configuration(proxyBeanMethods = false)
@ConditionalOnMissingBean(DataSource.class)
@ConditionalOnProperty(name = "spring.datasource.type")
static class Generic {

@Bean
DataSource dataSource(DataSourceProperties properties) {
//使用DataSourceBuilder创建数据源,利用反射创建响应type的数据源,并且绑定相关属性
return properties.initializeDataSourceBuilder().build();
}

}

4、DataSourceInitializer:ApplicationListener

​ 作用:

​ 1)、createSchema();运行建表语句;

​ 2)、runDataScripts();运行插入数据的sql语句;

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boolean createSchema() {
//向getScripts()传入参数fallback="schema"
List<Resource> scripts = getScripts("spring.datasource.schema", this.properties.getSchema(), "schema");
if (!scripts.isEmpty()) {
if (!isEnabled()) {
logger.debug("Initialization disabled (not running DDL scripts)");
return false;
}
String username = this.properties.getSchemaUsername();
String password = this.properties.getSchemaPassword();
runScripts(scripts, username, password);
}
return !scripts.isEmpty();
}

void initSchema() {
//向getScripts()传入参数fallback="data"
List<Resource> scripts = getScripts("spring.datasource.data", this.properties.getData(), "data");
if (!scripts.isEmpty()) {
if (!isEnabled()) {
logger.debug("Initialization disabled (not running data scripts)");
return;
}
String username = this.properties.getDataUsername();
String password = this.properties.getDataPassword();
runScripts(scripts, username, password);
}
}

private List<Resource> getScripts(String propertyName, List<String> resources, String fallback) {
if (resources != null) {
return getResources(propertyName, resources, true);
}
String platform = this.properties.getPlatform();
List<String> fallbackResources = new ArrayList<>();
//createSchema()传入fallback="schema",因此文件名为schema-all.sql/schema.sql
//initSchema()传入fallback="data",因此文件名为data-all.sql/data.sql
fallbackResources.add("classpath*:" + fallback + "-" + platform + ".sql");
fallbackResources.add("classpath*:" + fallback + ".sql");
return getResources(propertyName, fallbackResources, false);
}

x

默认只需要将文件命名为:

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schema-*.sql、data-*.sql
默认规则:schema.sql,schema-all.sql;
可以使用
schema:
- classpath:department.sql
指定位置
#在2.2.x开启应用启动建表
spring.datasource.initialization-mode=always

5、操作数据库:自动配置了JdbcTemplate操作数据库

JdbcTemplateAutoConfiguration导入了JdbcTemplateConfiguration类,而JdbcTemplateConfiguration类中向容器中添加了JdbcTemplate,因此我们可以使用JdbcTemplate操作数据库

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@Configuration(proxyBeanMethods = false)
@ConditionalOnClass({ DataSource.class, JdbcTemplate.class })
@ConditionalOnSingleCandidate(DataSource.class)
@AutoConfigureAfter(DataSourceAutoConfiguration.class)
@EnableConfigurationProperties(JdbcProperties.class)
@Import({ JdbcTemplateConfiguration.class, NamedParameterJdbcTemplateConfiguration.class })
public class JdbcTemplateAutoConfiguration {

}

@Configuration(proxyBeanMethods = false)
@ConditionalOnMissingBean(JdbcOperations.class)
class JdbcTemplateConfiguration {

//向容器中导入JdbcTemplate
@Bean
@Primary
JdbcTemplate jdbcTemplate(DataSource dataSource, JdbcProperties properties) {
JdbcTemplate jdbcTemplate = new JdbcTemplate(dataSource);
JdbcProperties.Template template = properties.getTemplate();
jdbcTemplate.setFetchSize(template.getFetchSize());
jdbcTemplate.setMaxRows(template.getMaxRows());
if (template.getQueryTimeout() != null) {
jdbcTemplate.setQueryTimeout((int) template.getQueryTimeout().getSeconds());
}
return jdbcTemplate;
}

}

2、整合Druid数据源

配置

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spring:
datasource:
username: root
password: 123
url: jdbc:mysql://127.0.0.1:3306/springboot?serverTimezone=Asia/Shanghai
driver-class-name: com.mysql.cj.jdbc.Driver
type: com.alibaba.druid.pool.DruidDataSource
# initialization-mode: always 开启启动建表

# 数据源其他配置
initialSize: 5
minIdle: 5
maxActive: 20
maxWait: 60000
timeBetweenEvictionRunsMillis: 60000
minEvictableIdleTimeMillis: 300000
validationQuery: SELECT 1 FROM DUAL
testWhileIdle: true
testOnBorrow: false
testOnReturn: false
poolPreparedStatements: true
# 配置监控统计拦截的filters,去掉后监控界面sql无法统计,'wall'用于防火墙
filters: stat,wall,log4j
maxPoolPreparedStatementPerConnectionSize: 20
useGlobalDataSourceStat: true
connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500

由于spring.datasource默认使用DataSourceProperties类进行配置,而DataSourceProperties中没有druid配置的各项属性,因此我们需要自定义配置类

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导入druid数据源
@Configuration
public class DruidConfig {

@ConfigurationProperties(prefix = "spring.datasource")
@Bean
public DataSource druid(){
return new DruidDataSource();
}

//配置Druid的监控
//1、配置一个管理后台的Servlet
@Bean
public ServletRegistrationBean statViewServlet(){
ServletRegistrationBean bean = new ServletRegistrationBean(new StatViewServlet(), "/druid/*");
Map<String,String> initParams = new HashMap<>();

initParams.put("loginUsername","admin");
initParams.put("loginPassword","123456");
initParams.put("allow","");//默认就是允许所有访问
initParams.put("deny","192.168.15.21");

bean.setInitParameters(initParams);
return bean;
}


//2、配置一个web监控的filter
@Bean
public FilterRegistrationBean webStatFilter(){
FilterRegistrationBean bean = new FilterRegistrationBean();
bean.setFilter(new WebStatFilter());

Map<String,String> initParams = new HashMap<>();
initParams.put("exclusions","*.js,*.css,/druid/*");

bean.setInitParameters(initParams);

bean.setUrlPatterns(Arrays.asList("/*"));

return bean;
}
}

3、整合MyBatis

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<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.3.1</version>
</dependency>

步骤:

​ 1)、配置数据源相关属性(见上一节Druid)

​ 2)、给数据库建表

​ 3)、创建JavaBean

4)、注解版

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//指定这是一个操作数据库的mapper
@Mapper
public interface DepartmentMapper {

@Select("select * from department where id=#{id}")
public Department getDeptById(Integer id);

@Delete("delete from department where id=#{id}")
public int deleteDeptById(Integer id);

@Options(useGeneratedKeys = true,keyProperty = "id")
@Insert("insert into department(departmentName) values(#{departmentName})")
public int insertDept(Department department);

@Update("update department set departmentName=#{departmentName} where id=#{id}")
public int updateDept(Department department);
}

问题:

自定义MyBatis的配置规则;给容器中添加一个ConfigurationCustomizer;

比如支持驼峰命名法:

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@Select("SELECT * FROM department where id=#{id}")
Department getDeptById(Integer id);

在不定制的情况下,departmentName是封装不进去的

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@org.springframework.context.annotation.Configuration
public class MyBatisConfig {

@Bean
public ConfigurationCustomizer configurationCustomizer(){
return new ConfigurationCustomizer(){

//开启驼峰命名法
@Override
public void customize(Configuration configuration) {
configuration.setMapUnderscoreToCamelCase(true);
}
};
}
}
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使用MapperScan批量扫描所有的Mapper接口;
@MapperScan(value = "com.atguigu.springboot.mapper")
@SpringBootApplication
public class SpringBoot06DataMybatisApplication {

public static void main(String[] args) {
SpringApplication.run(SpringBoot06DataMybatisApplication.class, args);
}
}

5)、配置文件版

配置文件可与注解同时生效,但相关配置(如驼峰命名法)需要单独各自配置

mybatis-config.xml

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<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<settings>
<!--指定开启驼峰命名法-->
<setting name="mapUnderscoreToCamelCase" value="true"/>
</settings>
</configuration>

EmployeeMapper.xml

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<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="cn.edu.ustc.springboot.mapper.EmployeeMapper">
<select id="getEmpById" resultType="cn.edu.ustc.springboot.bean.Employee">
select * from employee where id = #{id}
</select>
<insert id="insertEmp">
INSERT INTO employee(lastName,gender,email,d_id) VALUES (#{lastName},#{gender},#{email},#{dId})
</insert>
</mapper>
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mybatis:
config-location: classpath:mybatis/mybatis-config.xml 指定全局配置文件的位置
mapper-locations: classpath:mybatis/mapper/*.xml 指定sql映射文件的位置

更多使用参照

http://www.mybatis.org/spring-boot-starter/mybatis-spring-boot-autoconfigure/

4、整合SpringData JPA

1)、SpringData简介

2)、整合SpringData JPA

JPA:ORM(Object Relational Mapping);

1)、编写一个实体类(bean)和数据表进行映射,并且配置好映射关系;

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//使用JPA注解配置映射关系
@Entity //告诉JPA这是一个实体类(和数据表映射的类)
@Table(name = "tbl_user") //@Table来指定和哪个数据表对应;如果省略默认表名就是user;
public class User {

@Id //这是一个主键
@GeneratedValue(strategy = GenerationType.IDENTITY)//自增主键
private Integer id;

@Column(name = "last_name",length = 50) //这是和数据表对应的一个列
private String lastName;
@Column //省略默认列名就是属性名
private String email;

2)、编写一个Dao接口来操作实体类对应的数据表(Repository)

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//继承JpaRepository来完成对数据库的操作
public interface UserRepository extends JpaRepository<User,Integer> {
}

3)、基本的配置JpaProperties

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spring:
datasource:
username: root
password: 123
url: jdbc:mysql://localhost:3306/springboot?serverTimezone=Asia/Shanghai
driver-class-name: com.mysql.cj.jdbc.Driver
jpa:
#开启自动创建表或更新
hibernate:
ddl-auto: update
#开启打印sql语句
show-sql: true

七、启动配置原理

几个重要的事件回调机制

配置在META-INF/spring.factories

ApplicationContextInitializer

SpringApplicationRunListener

只需要放在ioc容器中

ApplicationRunner

CommandLineRunner

启动流程:

1、创建SpringApplication对象

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public SpringApplication(ResourceLoader resourceLoader, Class<?>... primarySources) {
this.resourceLoader = resourceLoader;
Assert.notNull(primarySources, "PrimarySources must not be null");
//保存主配置类
this.primarySources = new LinkedHashSet<>(Arrays.asList(primarySources));
//判断当前web应用类型(REACTIVE/SERVLET/NONE即非web)
this.webApplicationType = WebApplicationType.deduceFromClasspath();
//从类路径下找到META-INF/spring.factories配置的所有ApplicationContextInitializer;然后保存起来
setInitializers((Collection) getSpringFactoriesInstances(ApplicationContextInitializer.class));
//从类路径下找到ETA-INF/spring.factories配置的所有ApplicationListener
setListeners((Collection) getSpringFactoriesInstances(ApplicationListener.class));
//从多个配置类中找到有main方法的主配置类
this.mainApplicationClass = deduceMainApplicationClass();
}

2、运行run方法

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public ConfigurableApplicationContext run(String... args) {
StopWatch stopWatch = new StopWatch();
stopWatch.start();
ConfigurableApplicationContext context = null;
Collection<SpringBootExceptionReporter> exceptionReporters = new ArrayList<>();
configureHeadlessProperty();
//获取SpringApplicationRunListeners;从类路径下META-INF/spring.factories
SpringApplicationRunListeners listeners = getRunListeners(args);
//回调所有的获取SpringApplicationRunListener.starting()方法
listeners.starting();
try {
//封装命令行参数
ApplicationArguments applicationArguments = new DefaultApplicationArguments(args);
//准备环境
//创建环境完成后回调SpringApplicationRunListener.environmentPrepared();表示环境准备完成
ConfigurableEnvironment environment = prepareEnvironment(listeners, applicationArguments);
configureIgnoreBeanInfo(environment);
Banner printedBanner = printBanner(environment);
//创建ApplicationContext;根据webApplicationType创建SERVLET/REACTIVE/普通容器
context = createApplicationContext();
//获取SpringBootExceptionReporter;从类路径下META-INF/spring.factories
exceptionReporters = getSpringFactoriesInstances(SpringBootExceptionReporter.class,
new Class[] { ConfigurableApplicationContext.class }, context);
//准备上下文环境;将environment保存到ioc中;而且applyInitializers();
//applyInitializers():回调之前保存的所有的ApplicationContextInitializer的initialize方法
//回调所有的SpringApplicationRunListener的contextPrepared();
//prepareContext运行完成以后回调所有的SpringApplicationRunListener的contextLoaded();
prepareContext(context, environment, listeners, applicationArguments, printedBanner);
//刷新容器;ioc容器初始化(如果是Servlet应用还会创建嵌入式的Tomcat并启动);
//扫描,创建,加载所有组件的地方;(配置类,组件,自动配置)
refreshContext(context);
afterRefresh(context, applicationArguments);
stopWatch.stop();
if (this.logStartupInfo) {
new StartupInfoLogger(this.mainApplicationClass).logStarted(getApplicationLog(), stopWatch);
}
//回调所有的获取SpringApplicationRunListener.started()方法
listeners.started(context);
//从容器中分别获取ApplicationRunner和CommandLineRunner并调用其回调方法胜
//ApplicationRunner先回调,CommandLineRunner再回调
callRunners(context, applicationArguments);
}
catch (Throwable ex) {
handleRunFailure(context, ex, exceptionReporters, listeners);
throw new IllegalStateException(ex);
}

try {
//回调所有的获取SpringApplicationRunListener.running()方法
listeners.running(context);
}
catch (Throwable ex) {
handleRunFailure(context, ex, exceptionReporters, null);
throw new IllegalStateException(ex);
}
return context;
}

3、事件监听机制

配置在META-INF/spring.factories

ApplicationContextInitializer

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public class HelloApplicationContextInitializer implements ApplicationContextInitializer<ConfigurableApplicationContext> {
@Override
public void initialize(ConfigurableApplicationContext applicationContext) {
System.out.println("ApplicationContextInitializer...initialize..."+applicationContext);
}
}

SpringApplicationRunListener

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public class HelloSpringApplicationRunListener implements SpringApplicationRunListener {

//必须有的构造器
public HelloSpringApplicationRunListener(SpringApplication application, String[] args){

}

@Override
public void starting() {
System.out.println("SpringApplicationRunListener...starting...");
}

@Override
public void environmentPrepared(ConfigurableEnvironment environment) {
Object o = environment.getSystemProperties().get("os.name");
System.out.println("SpringApplicationRunListener...environmentPrepared.."+o);
}

@Override
public void contextPrepared(ConfigurableApplicationContext context) {
System.out.println("SpringApplicationRunListener...contextPrepared...");
}

@Override
public void contextLoaded(ConfigurableApplicationContext context) {
System.out.println("SpringApplicationRunListener...contextLoaded...");
}

@Override
public void finished(ConfigurableApplicationContext context, Throwable exception) {
System.out.println("SpringApplicationRunListener...finished...");
}
}

配置(META-INF/spring.factories)

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org.springframework.context.ApplicationContextInitializer=\
com.atguigu.springboot.listener.HelloApplicationContextInitializer

org.springframework.boot.SpringApplicationRunListener=\
com.atguigu.springboot.listener.HelloSpringApplicationRunListener

只需要放在ioc容器中

ApplicationRunner

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@Component
public class HelloApplicationRunner implements ApplicationRunner {
@Override
public void run(ApplicationArguments args) throws Exception {
System.out.println("ApplicationRunner...run....");
}
}

CommandLineRunner

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@Component
public class HelloCommandLineRunner implements CommandLineRunner {
@Override
public void run(String... args) throws Exception {
System.out.println("CommandLineRunner...run..."+ Arrays.asList(args));
}
}

八、自定义starter

starter:

​ 1、这个场景需要使用到的依赖是什么?

​ 2、如何编写自动配置

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@Configuration  //指定这个类是一个配置类
@ConditionalOnXXX //在指定条件成立的情况下自动配置类生效
@AutoConfigureAfter //指定自动配置类的顺序
@Bean //给容器中添加组件

@ConfigurationPropertie结合相关xxxProperties类来绑定相关的配置
@EnableConfigurationProperties //让xxxProperties生效加入到容器中

自动配置类要能加载
将需要启动就加载的自动配置类,配置在META-INF/spring.factories
org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
org.springframework.boot.autoconfigure.admin.SpringApplicationAdminJmxAutoConfiguration,\
org.springframework.boot.autoconfigure.aop.AopAutoConfiguration,\

​ 3、模式:

启动器只用来做依赖导入;

专门来写一个自动配置模块;

启动器依赖自动配置;别人只需要引入启动器(starter)

mybatis-spring-boot-starter;自定义启动器名-spring-boot-starter

步骤:

1)、启动器模块

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<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>

<groupId>com.atguigu.starter</groupId>
<artifactId>atguigu-spring-boot-starter</artifactId>
<version>1.0-SNAPSHOT</version>

<!--启动器-->
<dependencies>

<!--引入自动配置模块-->
<dependency>
<groupId>com.atguigu.starter</groupId>
<artifactId>atguigu-spring-boot-starter-autoconfigurer</artifactId>
<version>0.0.1-SNAPSHOT</version>
</dependency>
</dependencies>

</project>

2)、自动配置模块

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<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>

<groupId>com.atguigu.starter</groupId>
<artifactId>atguigu-spring-boot-starter-autoconfigurer</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>

<name>atguigu-spring-boot-starter-autoconfigurer</name>
<description>Demo project for Spring Boot</description>

<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.10.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>

<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>

<dependencies>

<!--引入spring-boot-starter;所有starter的基本配置-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>

</dependencies>



</project>
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package com.atguigu.starter;

import org.springframework.boot.context.properties.ConfigurationProperties;

@ConfigurationProperties(prefix = "atguigu.hello")
public class HelloProperties {

private String prefix;
private String suffix;

public String getPrefix() {
return prefix;
}

public void setPrefix(String prefix) {
this.prefix = prefix;
}

public String getSuffix() {
return suffix;
}

public void setSuffix(String suffix) {
this.suffix = suffix;
}
}
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package com.atguigu.starter;

public class HelloService {

HelloProperties helloProperties;

public HelloProperties getHelloProperties() {
return helloProperties;
}

public void setHelloProperties(HelloProperties helloProperties) {
this.helloProperties = helloProperties;
}

public String sayHellAtguigu(String name){
return helloProperties.getPrefix()+"-" +name + helloProperties.getSuffix();
}
}
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package com.atguigu.starter;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
@ConditionalOnWebApplication //web应用才生效
@EnableConfigurationProperties(HelloProperties.class)
public class HelloServiceAutoConfiguration {

@Autowired
HelloProperties helloProperties;
@Bean
public HelloService helloService(){
HelloService service = new HelloService();
service.setHelloProperties(helloProperties);
return service;
}
}

更多SpringBoot整合示例

https://github.com/spring-projects/spring-boot/tree/master/spring-boot-samples

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