Hello, SpringMVC
springMVC 的执行流程
- 具体流程
（1）当用户通过浏览器发起一个HTTP请求，请求直接到前端控制器DispatcherServlet；
（2）前端控制器接收到请求以后调用处理器映射器HandlerMapping，处理器映射器根据请求的URL找到具体的Handler，并将它返回给前端控制器；
（3）前端控制器调用处理器适配器HandlerAdapter去适配调用Handler；
（4）处理器适配器会根据Handler去调用真正的处理器去处理请求，并且处理对应的业务逻辑；
（5）当处理器处理完业务之后，会返回一个ModelAndView对象给处理器适配器，HandlerAdapter再将该对象返回给前端控制器；这里的Model是返回的数据对象，View是逻辑上的View。
（6）前端控制器DispatcherServlet将返回的ModelAndView对象传给视图解析器ViewResolver进行解析，解析完成之后就会返回一个具体的视图View给前端控制器。（ViewResolver根据逻辑的View查找具体的View）
（7）前端控制器DispatcherServlet将具体的视图进行渲染，渲染完成之后响应给用户（浏览器显示）。
SpringMVC使用的配置
1. pom.xml配置依赖和资源导入配置
<?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>org.example</groupId>
<artifactId>SpringMVC</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>pom</packaging>
<modules>
<module>springmvc-hello</module>
<module>springmvc-01-annotation</module>
</modules>
<properties>
<maven.compiler.source>17</maven.compiler.source>
<maven.compiler.target>17</maven.compiler.target>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/com.mysql/mysql-connector-j -->
<dependency>
<groupId>com.mysql</groupId>
<artifactId>mysql-connector-j</artifactId>
<version>8.0.33</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.mybatis/mybatis -->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.5.13</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>6.0.11</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>6.0.11</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.aspectj/aspectjweaver -->
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
<version>1.9.19</version>
<scope>runtime</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/org.mybatis/mybatis-spring -->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis-spring</artifactId>
<version>3.0.2</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.projectlombok/lombok -->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.28</version>
<scope>provided</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/jakarta.servlet/jakarta.servlet-api -->
<dependency>
<groupId>jakarta.servlet</groupId>
<artifactId>jakarta.servlet-api</artifactId>
<version>6.0.0</version>
<scope>provided</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/jakarta.servlet.jsp/jakarta.servlet.jsp-api -->
<dependency>
<groupId>jakarta.servlet.jsp</groupId>
<artifactId>jakarta.servlet.jsp-api</artifactId>
<version>3.1.1</version>
<scope>provided</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/jakarta.servlet.jsp.jstl/jakarta.servlet.jsp.jstl-api -->
<dependency>
<groupId>jakarta.servlet.jsp.jstl</groupId>
<artifactId>jakarta.servlet.jsp.jstl-api</artifactId>
<version>3.0.0</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.taglibs/taglibs-standard-spec -->
<dependency>
<groupId>org.apache.taglibs</groupId>
<artifactId>taglibs-standard-spec</artifactId>
<version>1.2.5</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.taglibs/taglibs-standard-impl -->
<dependency>
<groupId>org.apache.taglibs</groupId>
<artifactId>taglibs-standard-impl</artifactId>
<version>1.2.5</version>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.glassfish.web</groupId>
<artifactId>jakarta.servlet.jsp.jstl</artifactId>
<version>2.0.0</version>
</dependency>
<!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.48</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.13.2</version>
<scope>compile</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/com.alibaba.fastjson2/fastjson2 -->
<dependency>
<groupId>com.alibaba.fastjson2</groupId>
<artifactId>fastjson2</artifactId>
<version>2.0.38</version>
</dependency>
</dependencies>
<build>
<resources>
<resource>
<directory>src/main/java</directory>
<includes>
<include>**/*.properties</include>
<include>**/*.xml</include>
</includes>
<filtering>false</filtering>
</resource>
<resource>
<directory>src/main/resources</directory>
<includes>
<include>**/*.properties</include>
<include>**/*.xml</include>
</includes>
<filtering>false</filtering>
</resource>
</resources>
</build>
</project>
2. web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
version="4.0">
<!--1.注册servlet-->
<servlet>
<servlet-name>SpringMVC</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<!--通过初始化参数指定SpringMVC配置文件的位置，进行关联-->
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:springmvc-servlet.xml</param-value>
</init-param>
<!-- 启动顺序，数字越小，启动越早 -->
<load-on-startup>1</load-on-startup>
</servlet>
<!--所有请求都会被springmvc拦截 -->
<servlet-mapping>
<servlet-name>SpringMVC</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
<!-- spring 自带的解决中文乱码的filter -->
<filter>
<filter-name>encoding</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>utf-8</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>encoding</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
</web-app>
3. springmvc.xml(spring的配置文件)
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
https://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/mvc
https://www.springframework.org/schema/mvc/spring-mvc.xsd">
<!-- 自动扫描包，让指定包下的注解生效,由IOC容器统一管理 -->
<context:component-scan base-package="com.mao.controller"/>
<!-- 让Spring MVC不处理静态资源 -->
<mvc:default-servlet-handler />
<!--
支持mvc注解驱动
在spring中一般采用@RequestMapping注解来完成映射关系
要想使@RequestMapping注解生效
必须向上下文中注册DefaultAnnotationHandlerMapping
和一个AnnotationMethodHandlerAdapter实例
这两个实例分别在类级别和方法级别处理。
而annotation-driven配置帮助我们自动完成上述两个实例的注入。
-->
<mvc:annotation-driven />
<!-- 视图解析器 -->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"
id="internalResourceViewResolver">
<!-- 前缀 -->
<property name="prefix" value="/WEB-INF/jsp/" />
<!-- 后缀 -->
<property name="suffix" value=".jsp" />
</bean>
</beans>
4. 示例Controller.java
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
public class HelloController {
@RequestMapping("hello")
public String hello(Model model){
model.addAttribute("title","hello");
model.addAttribute("msg","hello springMVC by annotation");
return "hello";
}
}
