SpringMvc接受请求参数的几种情况演示
- 2021 年 7 月 23 日
- 筆記
说明:
通常get请求获取的参数是在url后面,而post请求获取的是请求体当中的参数。因此两者在请求方式上会有所不同。
1.直接将接受的参数写在controller对应方法的形参当中(适用于get提交方式)
1 /** 2 * 1.直接把表单的参数写在Controller相应的方法的形参中 3 * 4 * @param username 5 * @param password 6 * @return 7 */ 8 @GetMapping("/addUser1") 9 public String addUser1(String username, String password) { 10 System.out.println ("username is:" + username); 11 System.out.println ("password is:" + password); 12 return username + "," + password; 13 }
2.通过url请求路径获取参数
1 /** 2 * 2、通过@PathVariable获取路径中的参数 3 * 4 * @param username 5 * @param password 6 * @return 7 */ 8 @RequestMapping(value = "/addUser4/{username}/{password}", method = RequestMethod.GET) 9 public String addUser4(@PathVariable String username, @PathVariable String password) { 10 System.out.println ("username is:" + username); 11 System.out.println ("password is:" + password); 12 return "addUser4"; 13 }
3.通过request请求对象来接受发来的参数信息(Get请求方式或者时Post请求方式都可以)
1 /** 2 * 3、通过HttpServletRequest接收 3 * 4 * @param request 5 * @return 6 */ 7 @RequestMapping("/addUser2") 8 public String addUser2(HttpServletRequest request) { 9 String username = request.getParameter ("username"); 10 String password = request.getParameter ("password"); 11 System.out.println ("username is:" + username); 12 System.out.println ("password is:" + password); 13 return "demo/index"; 14 }
4.封装JavaBean对象的方式来接受请求参数(get方式与post方式都可以)
4.1首先在模块当中创建对应的JavaBean,并提供相应的get,set方法。
1 package com.example.demo.pojo; 2 3 import lombok.Data; 4 5 @Data 6 public class User1 { 7 private String username; 8 private String password; 9 }
4.2Controller层
1 /** 2 * 4、通过一个bean来接收 3 * 4 * @param user 5 * @return 6 */ 7 @RequestMapping("/addUser3") 8 public String addUser3(User1 user) { 9 System.out.println ("username is:" + user.getUsername ( )); 10 System.out.println ("password is:" + user.getPassword ( )); 11 return "/addUser3"; 12 }
5.使用注解@RequestParam注解将请求参数绑定到Controller层对应方法的形参当中
1 /** 2 * 5、用注解@RequestParam绑定请求参数到方法入参 3 * @param username 4 * @param password 5 * @return 6 */ 7 @RequestMapping(value="/addUser6",method=RequestMethod.GET) 8 public String addUser6(@RequestParam("username") String username,@RequestParam("password") String password) { 9 System.out.println("username is:"+username); 10 System.out.println("password is:"+password); 11 return "demo/index"; 12 }
下面介绍,发送json格式的请求,接受数据的情况:
1.将json请求的key,value值封装到实体对象的属性当中(通常将参数放在请求体body中,以application/json格式被后端获取)
1.1创建一个实体类
1 public class User2 implements Serializable { 2 private static final long serialVersionUID = 1L; 3 @JsonProperty(value = "id") 4 private Integer id; 5 @JsonProperty(value = "name") 6 private String name; 7 @JsonProperty(value = "age") 8 private Integer age; 9 @JsonProperty(value = "hobby") 10 private List<String> hobby;
1 /** 2 *将json请求的key,value封装到实体对象当中。 3 * @param user 4 * @return 5 */ 6 @PostMapping("/save") 7 public String saveUser(@RequestBody User2 user) { 8 // list.add(user); 9 // User2 user2 = new User2 ( ); 10 // user2.setId (user.getId ()); 11 // user2.setAge (user.getAge ()); 12 // user2.setName (user.getName ()); 13 // user2.setHobby (user.getHobby ()); 14 return "success"+user; 15 }
2.将json请求的key,value值封装到request对象的属性当中(通常请求参数放body中,将content-type改为x-www-form-urlencoded)
1 /** 2 * 将请求参数封装到request对象当中。 3 * @param request 4 * @return 5 */ 6 @PostMapping("/save2") 7 public User2 save(HttpServletRequest request) { 8 Integer id = Integer.parseInt(request.getParameter("id")); 9 String name = request.getParameter("name"); 10 Integer age = Integer.parseInt(request.getParameter("age")); 11 String parameter = request.getParameter("hobby"); 12 List<String> stringList = new ArrayList<> ( ); 13 14 String[] split = parameter.split (","); 15 for (int i = split.length - 1; i >= 0; i--) { 16 stringList.add (split[i]); 17 } 18 19 User2 user2 = new User2(id, name, age, stringList); 20 // list.add(user); 21 return user2; 22 }
3.通过http协议,将json参数转成JSONOBject对象
3.1Controller层接受JSON参数
1 /** 2 * 通过http协议将参数转为jsonobject 3 * @param request 4 * @return 5 * @throws IOException 6 * @throws JSONException 7 */ 8 @PostMapping("/save3") 9 public User2 save3(HttpServletRequest request) throws IOException, JSONException { 10 11 JSONObject jsonObject = handlerData(request); 12 Integer id = jsonObject.getInteger("id"); 13 String name = jsonObject.getString("name"); 14 Integer age = jsonObject.getInteger("age"); 15 List<String> hobby = jsonObject.getObject("hobby", List.class); 16 User2 user3 = new User2 (id, name, age, hobby); 17 // list.add(user); 18 return user3; 19 }
3.2通过以下方法将Json字符串转成Jsonobject对象
1 //这里使用的是alibaba的json工具类 2 public static JSONObject handlerData(HttpServletRequest request) throws IOException, JSONException { 3 StringBuffer sb = new StringBuffer(); 4 InputStream is = request.getInputStream(); 5 BufferedReader br = new BufferedReader(new InputStreamReader (is, "utf-8")); 6 String s = ""; 7 while ((s = br.readLine()) != null) { 8 sb.append(s); 9 } 10 if (sb.toString().length() <= 0) { 11 return null; 12 } else { 13 return JSONObject.parseObject(sb.toString()); 14 } 15 }
4.将json格式的请求参数封装到hashmap的key,value键-值对当中。(json字符串串放在body中,请求格式为application/json格式)
1 /** 2 *将json请求的Key,value封装到map的key,value当中去。 3 * @param map 4 * @return 5 */ 6 @PostMapping("/save1") 7 public User2 saveUser1(@RequestBody Map<String, Object> map) { 8 Integer id = (Integer) map.get("id"); 9 String name = (String) map.get("name"); 10 Integer age = (Integer) map.get("age"); 11 List<String> hobby=(List<String>) map.get("hobby"); 12 User2 user = new User2(id, name, age, hobby); 13 // list.add(user); 14 return user; 15 }
该文档主要是学习以下两篇文档的总结:
//www.cnblogs.com/lirenhe/p/10737673.html
//blog.csdn.net/zyxwvuuvwxyz/article/details/80352712