SpringMVC注解使用

SpringMVC注解使用

1. 导包

   <dependencies>  
       <!-- https://mvnrepository.com/artifact/javax.servlet/javax.servlet-api -->
       <dependency>
           <groupId>javax.servlet</groupId>
           <artifactId>javax.servlet-api</artifactId>
           <version>4.0.1</version>
       </dependency>
   
       <!-- https://mvnrepository.com/artifact/javax.servlet.jsp/jsp-api -->
       <dependency>
           <groupId>javax.servlet.jsp</groupId>
           <artifactId>jsp-api</artifactId>
           <version>2.1</version>
       </dependency>
   
       <dependency>
           <groupId>javax.servlet</groupId>
           <artifactId>jstl</artifactId>
           <version>1.2</version>
       </dependency>
       <!-- https://mvnrepository.com/artifact/taglibs/standard -->
       <dependency>
           <groupId>taglibs</groupId>
           <artifactId>standard</artifactId>
           <version>1.1.2</version>
       </dependency>
       <!--Junit        -->
       <dependency>
           <groupId>junit</groupId>
           <artifactId>junit</artifactId>
           <version>4.13.1</version>
       </dependency>
       <!--spring      -->
       <dependency>
           <groupId>org.springframework</groupId>
           <artifactId>spring-webmvc</artifactId>
           <version>5.3.3</version>
       </dependency>
   </dependencies>
   <!--解决resources下静态资源无法导出    -->
   <build>
       <resources>
           <resource>
               <directory>src/main/resources</directory>
               <includes>
                   <include>**/*.properties</include>
                   <include>**/*.xml</include>
               </includes>
               <filtering>true</filtering>
           </resource>
   
           <resource>
               <directory>src/main/java</directory>
               <includes>
                   <include>**/*.properties</include>
                   <include>**/*.xml</include>
               </includes>
               <filtering>true</filtering>
           </resource>
       </resources>
   </build>
   

2. web.xml配置文件

   <!--配置 DispatcherServlet   -->
   <servlet>
       <servlet-name>springmvc</servlet-name>
       <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
       <init-param>
           <param-name>contextConfigLocation</param-name>
           <param-value>classpath:springmvc-servlet.xml</param-value>
       </init-param>
       <load-on-startup>1</load-on-startup>
   </servlet>
   
   <servlet-mapping>
       <servlet-name>springmvc</servlet-name>
       <url-pattern>/</url-pattern>
   </servlet-mapping>
   

3. springmvc-servlet.xml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
                              https://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">
   
       <!--扫描包下的注解    -->
       <context:component-scan base-package="cn.gbl"/>
       <!--让mvc不处理静态资源（.css .js .html .mp3等）    -->
       <mvc:default-servlet-handler/>
       <!--取代处理器映射器和处理器适配器    -->
       <mvc:annotation-driven/>
   
       <!--视图解析器-->
       <bean id="internalResourceViewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
           <!-- 前缀       -->
           <property name="prefix" value="/WEB-INF/jsp/"/>
           <!-- 后缀      -->
           <property name="suffix" value=".jsp"/>
       </bean>
   </beans>
   

4. 创建controller

   @Controller
   //@RestController 使用此注解，这个Controller类就不会被视图解析器解析，直接返回Json形式的字符串
   public class Hello {
       @RequestMapping("/hello")
       public String hello(Model model){
           String msg="hello!!!!";
           model.addAttribute("msg",msg);
           return "hello";//会被视图解析器处理，跳转到hello.jsp
       }
   }
   

5. 视图层

   <%@ page contentType="text/html;charset=UTF-8" language="java" %>
   <html>
   <head>
       <title>Title</title>
   </head>
   <body>
       ${msg}
   </body>
   </html>
   

6. 测试：