请求

1. @RequestParam ```java package com.itheima.mvctest.controller;

import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.bind.annotation.RestController;

/**

• @author liqp
• @version 1.0

• @date 2021/11/22 / @RestController @RequestMapping(“user”) public class UserController { /*

  • http://localhost:8080/user/get1?userName=zhangsan

  • @param userName */ @GetMapping(“get1”) public void get1(String userName){ System.out.println(userName); }

    /**

  • @RequestParam 请求参数 http://localhost:8080/user/get2?userName=zhangsan
  • @param userName2 */ @GetMapping(“get2”) public void get2(@RequestParam(“userName”) String userName2){ System.out.println(userName2); } }

2. @PathVarible
```java
/**
     * PathVariable 路径变量 http://localhost:8080/user/get3/2
     * @param id
     */
    @GetMapping("get3/{id}")
    public void get3(@PathVariable("id") Integer id){
        System.out.println(id);
    }

1. @ReuqestBody

   /**
     * localhost:8080/user/get4
     * body:
     * {
     *     "id":1,
     *     "userName":"zhangsan",
     *     "password":"123"
     * }
     * @param user
     */
    @GetMapping("get4")
    public void get4(@RequestBody User user){
        System.out.println(user);
    }
   

   

响应

1. 响应json字符串 ```java /*
   • @return 返回json字符串 */ @GetMapping(“get5”) public User get5() { User user = new User(); user.setId(1); user.setUserName(“zhangsan”); user.setPassword(“123”); return user; }

2. _ResponseEntity 响应200_
```java
/**
     *
     * @return ResponseEntity 指定响应体
     */
    @GetMapping("get6")
    public ResponseEntity<User> get6() {
        User user = new User();
        user.setId(1);
        user.setUserName("zhangsan");
        user.setPassword("123");
        return ResponseEntity.ok(user);
    }

1. ResponseEntity 自定义状态码 ```java /**

   • 自定义状态码

   • @return */ @GetMapping(“get7”) public ResponseEntity get7() { User user = new User(); user.setId(1); user.setUserName(“zhangsan”); user.setPassword(“123”); //返回404 //return ResponseEntity.status(HttpStatus.NOT_FOUND).body(user);

     //返回500 return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(user); }

4. _ResponseEntity 定义响应头_
```java
/**
     *   自定义响应头
     * @return
     */
    @GetMapping("get8")
    public ResponseEntity<User> get8() {
        User user = new User();
        user.setId(1);
        user.setUserName("zhangsan");
        user.setPassword("123");
        //return ResponseEntity.ok().header("itcats", "itheima").body(user);
        //指定状态码为500 ，设置响应头：itcats:itheima, 设置响应体：user
        return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).header("itcats", "itheima").body(user);
    }