【JavaEE案例】Spring MVC的核心类和注解

淩亂°似流年 2024-03-22 19:47 84阅读 0赞

案例介绍

在客户端发送GET、POST、PUT、DELETE请求，由Spring MVC接收请求并响应。

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案例实现

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1.利用Maven创建一个web应用

[参考步骤1][1]

2.引入对Spring和SpringMVC的依赖**pom.xml**

<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/maven-v4_0_0.xsd">
      <modelVersion>4.0.0</modelVersion>
    
      <groupId>com.itheima</groupId>
      <artifactId>SpringMVC</artifactId>
      <packaging>war</packaging>
    
      <version>1.0-SNAPSHOT</version>
      <name>SpringMVC Maven Webapp</name>
      <url>http://maven.apache.org</url>
      <dependencies>
        <dependency>
          <groupId>junit</groupId>
          <artifactId>junit</artifactId>
          <version>4.13.2</version>
          <scope>test</scope>
        </dependency>
        <dependency>
          <groupId>org.springframework</groupId>
          <artifactId>spring-context</artifactId>
          <version>5.3.16</version>
        </dependency>
        <dependency>
          <groupId>org.springframework</groupId>
          <artifactId>spring-test</artifactId>
          <version>5.3.16</version>
        </dependency>
        <dependency>
          <groupId>org.springframework</groupId>
          <artifactId>spring-webmvc</artifactId>
          <version>5.3.16</version>
        </dependency>
        
        <dependency>
          <groupId>javax.servlet</groupId>
          <artifactId>javax.servlet-api</artifactId>
          <version>4.0.1</version>
          <scope>provided</scope>
        </dependency>
        
        <dependency>
          <groupId>javax.servlet.jsp</groupId>
          <artifactId>javax.servlet.jsp-api</artifactId>
          <version>2.3.3</version>
          <scope>provided</scope>
        </dependency>
      </dependencies>
      <build>
        <finalName>SpringMVC</finalName>
      </build>
    </project>

3.配置web运行的Tomcat服务器

[参考1.配置Web运行的Tomcat服务器和2.Tomcat:HTTP状态 404][1._Web_Tomcat_2.Tomcat_HTTP_ 404]

4.配置前端控制器**web.xml**：Spring MVC通过前端控制器拦截客户端的请求并进行转发

<!DOCTYPE web-app PUBLIC
            "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
            "http://java.sun.com/dtd/web-app_2_3.dtd" >
    
    <web-app>
      <display-name>Restful Api Application</display-name>
      <servlet>
        <servlet-name>app</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
          <param-name>contextConfigLocation</param-name>
          <param-value>classpath:applicationContext.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
      </servlet>
      <servlet-mapping>
        <servlet-name>app</servlet-name>
        <url-pattern>/</url-pattern>
      </servlet-mapping>
    </web-app>

5.配置处理器映射信息和视图解析器**applicationContext.xml**

<?xml version="1.0" encoding="UTF-8"?>
    <beans xmlns="http://www.springframework.org/schema/beans"
           xmlns:context="http://www.springframework.org/schema/context"
           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
           http://www.springframework.org/schema/context
           http://www.springframework.org/schema/context/spring-context.xsd">
        
        <context:component-scan base-package="com.itheima.controllers"/>
        
        <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
            
        </bean>
    </beans>

6.创建处理器**UserController.java**：用于处理客户端的请求并指定响应时跳转的页面

package com.itheima.controllers;
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.*;
    
    @Controller
    @RequestMapping("/user")
    public class UserController {
        @GetMapping(value="/1")
        public void getUserById() {
            System.out.println("Find user with id 1");
        }
    
        @PostMapping
        public void addUser(String username) {
            System.out.println("Add " + username);
        }
    
        @PutMapping(value="/1")
        public void updateUser() {
            System.out.println("Update a user with id 1");
        }
    
        @DeleteMapping (value="/1")
        public void deleteUser() {
            System.out.println("Delete a user with id 1");
        }
    }

7.启动项目并测试应用：在IDEA中运行程序，复制网址到Apifox中，（打开Apifox→新建接口），点击**'发送'**按钮，回到IDEA查看运行结果。

[测试工具Apifox下载][Apifox]

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[3ce63ac2de944cf88a8ecaae878823a7.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/18/d8543e0fdd6b4c0a8000f6210c0839f9.png
[a1f5dfe7a8a649848d6ee55272b7a2f6.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/18/16a0548902f64e07ac2d5c0384e6633f.png
[1]: https://blog.csdn.net/weixin_66697650/article/details/130659717
[1._Web_Tomcat_2.Tomcat_HTTP_ 404]: https://blog.csdn.net/weixin_66697650/article/details/130657403
[Apifox]: https://apifox.com/compare/postman-vs-apifox/
[0d3beb4fb6d647a9b9d28adc6b01e53d.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/18/684be7e8dca34247a9997b6f7079967e.png
[ffff04099907499496376fd6a538df4d.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/18/335e84e4ea024d70af0fdd5e9bcba057.png
[a28068f25fcb4c5ca4bb8e5ef88e6b02.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/18/d40e749d8b39492d89fbd7a575054f18.png
[88ab936fe9574f688aff1292ac95901d.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/18/8cbd860d278348b0a82c2792b5a7b006.png
[40ae859bd67142709cf1f23e8f25b13f.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/18/81730b8753ef4abaaf6740a9988939cb.png
[bf6962506e4d412e8f731f5aad5a0e63.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/18/5df059bd0ee54cda8e4b29e51e9d08a0.png