java获取请求参数案例代码和设置响应数据

java获取请求参数案例代码

1. package com.jinhei;
   
2. 
   
3. import jakarta.servlet.http.HttpServletRequest;
   
4. import org.springframework.web.bind.annotation.RequestMapping;
   
5. import org.springframework.web.bind.annotation.RestController;
   
6. 
   
7. @RestController
   
8. public class RequestController {
   
9.     /**
   
10.      * 请求路径 http://localhost:8080/request?name=Tom&age=18
    
11.      * @param request
    
12.      * @return
    
13.      */
    
14.     @RequestMapping("/request")
    
15.     public String request(HttpServletRequest request){
    
16.         //1.获取请求参数 name, age
    
17.         String name = request.getParameter("name");
    
18.         String age = request.getParameter("age");
    
19.         System.out.println("name = " + name + ", age = " + age);
    
20. 
    
21.         //2.获取请求路径
    
22.         String uri = request.getRequestURI();
    
23.         String url = request.getRequestURL().toString();
    
24.         System.out.println("uri = " + uri);
    
25.         System.out.println("url = " + url);
    
26. 
    
27.         //3.获取请求方式
    
28.         String method = request.getMethod();
    
29.         System.out.println("method = " + method);
    
30. 
    
31.         //4.获取请求头
    
32.         String header = request.getHeader("User-Agent");
    
33.         System.out.println("header = " + header);
    
34.         return "request success";
    
35.     }
    
36. }
    

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输出结果如下：

name = Tom, age = 18
uri = /request
url = http://localhost:8080/request
method = GET
header = Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/121.0.0.0 Safari/537.36

1. package com.jinhei;
   
2. 
   
3. import jakarta.servlet.http.HttpServletResponse;
   
4. import org.springframework.http.ResponseEntity;
   
5. import org.springframework.web.bind.annotation.RequestMapping;
   
6. import org.springframework.web.bind.annotation.RestController;
   
7. 
   
8. import java.io.IOException;
   
9. 
   
10. @RestController
    
11. public class ResponseController {
    
12. 
    
13.     @RequestMapping("/response")
    
14.     public void response(HttpServletResponse response) throws IOException {
    
15.         //1.设置响应状态码
    
16.         response.setStatus(401);
    
17.         //2.设置响应头
    
18.         response.setHeader("name","itcast");
    
19.         //3.设置响应体
    
20.         response.setContentType("text/html;charset=utf-8");
    
21.         response.setCharacterEncoding("utf-8");
    
22.         response.getWriter().write("<h1>hello response</h1>");
    
23.     }
    
24. 
    
25.     @RequestMapping("/response2")
    
26.     public ResponseEntity<String> response2(HttpServletResponse response) throws IOException {
    
27.         return ResponseEntity
    
28.                 .status(401)
    
29.                 .header("name","itcast")
    
30.                 .body("<h1>hello response</h1>");
    
31.     }
    
32. 
    
33. }

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/**
* 删除部门 - 方式二: @RequestParam
* 注意事项: 一旦声明了@RequestParam, 该参数在请求时必须传递, 如果不传递将会报错. (默认 required 为 true)
*/
/*@DeleteMapping("/depts")
public Result delete(@RequestParam(value = "id", required = false) Integer deptId){
    System.out.println("根据ID删除部门: " + deptId);
    return Result.success();
}*/
@RequestParam注解required属性默认为true，代表该参数必须传递，如果不传递将报错。 如果参数可选，可以将属性设置为false。

/**
* 删除部门 - 方式三: 省略@RequestParam (前端传递的请求参数名与服务端方法形参名一致) [推荐]
*  delete htt p://localhost:8080/depts?id=1
*/
@DeleteMapping
public Result delete(Integer id){
    //System.out.println("根据ID删除部门: " + id);
log.info("根据ID删除部门: {}", id);
    deptService.deleteById(id);
    return Result.success();
}