SpringMVC中@RequestBody和@ResponseBody注解的使用
@RequestBody
@RequestBody注解可以获取请求体，控制器方法的形参如果使用@RequestBody注解进行标识，当前请求的请求体就会为该注解所标识的形参赋值。
controller如下：
package com.lalala.controller;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
public class HttpController {
@RequestMapping("/testRequestBody")
public String testRequestBody(@RequestBody String requestBody) {
System.out.println("requestBody:" + requestBody);
return "success";
}
}
index.html如下：
<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="UTF-8">
<title>首页</title>
</head>
<body>
<h1>首页</h1>
<form th:action="@{/testRequestBody}" method="post">
用户名：<input type="text" name="username"><br>
密码：<input type="password" name="password"><br>
<input type="submit" value="测试@RequestBody">
</form>
</body>
</html>
RequestEntity
RequestEntity是封装请求报文的一种类型，需要在控制器方法的形参中设置该类型的形参，当前请求的请求报文就会赋值给该形参，可以通过getHeaders()获取请求头信息，通过getBody()获取请求体信息。
controller如下：
package com.lalala.controller;
import org.springframework.http.RequestEntity;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
public class HttpController {
@RequestMapping("/testRequestEntity")
public String testRequestEntity(RequestEntity<String> requestEntity) {
//当前requestEntity表示整个请求报文的信息
System.out.println("requestHeader:" + requestEntity.getHeaders());
System.out.println("requestBody:" + requestEntity.getBody());
return "success";
}
}
index.html如下：
<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="UTF-8">
<title>首页</title>
</head>
<body>
<h1>首页</h1>
<form th:action="@{/testRequestEntity}" method="post">
用户名：<input type="text" name="username"><br>
密码：<input type="password" name="password"><br>
<input type="submit" value="测试RequestEntity">
</form>
</body>
</html>
@ResponseBody
@ResponseBody用于标识一个控制器方法，可以将该方法的返回值直接作为响应报文的响应体响应到浏览器。
package com.lalala.controller;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
@Controller
public class HttpController {
@RequestMapping("/testResponseBody")
@ResponseBody
public String testResponseBody(){
return "hello,success";
}
}
@ResponseBody处理json
首先导入jackson依赖
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.12.1</version>
</dependency>
新建User类：
package com.lalala.controller.bean;
public class User {
private Integer id;
private String username;
private String password;
private Integer age;
private String sex;
...
}
controller如下：
package com.lalala.controller;
import com.lalala.controller.bean.User;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
@Controller
public class HttpController {
@RequestMapping("/testResponseUser")
@ResponseBody
public User testResponseUser(){
return new User(110,"admin","123456",18,"男");
}
}
浏览器显示如下：
{
id: 110,
username: "admin",
password: "123456",
age: 18,
sex: "男"
}
@RestController
@RestController注解是springMVC提供的一个复合注解，标识在控制器的类上，就相当于为类添加了@Controller注解，并且为其中的每个方法添加了@ResponseBody注解。
ResponseEntity
ResponseEntity用于控制器方法的返回值类型，该控制器方法的返回值就是响应到浏览器的响应报文。
