一、创建一个springBoot个项目
二、编写实体类
/**
* 返回Json数据实体类
*/
public class User {
private int id;
private String username;
private String password; public String getPassword() {
return password;
} public void setPassword(String password) {
this.password = password;
} public String getUsername() {
return username;
} public void setUsername(String username) {
this.username = username;
} public int getId() {
return id;
} public void setId(int id) {
this.id = id;
}
}
三、编写控制层Controller类
import com.example.bean.User;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController; /**
*Json返回数据的Controller
*/
@RestController
@RequestMapping("user")
public class ReturnJsoncontroller { @RequestMapping("getUser")
public User getUser(){
User user = new User();
user.setId(1);
user.setUsername("loaderman");
user.setPassword("123123");
return user;
}
}
四、测试返回Json数据
浏览器输入http://localhost:8080/user/getUser
输出:
{"id":1,"username":"loaderman","password":"123123"}返回listjson数据:
控制类:
package com.generalichina.cimc.controller; import com.generalichina.cimc.bean.User;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController; import java.util.ArrayList;
import java.util.List; /**
* Json返回数据的Controller
*/
@RestController
@RequestMapping("user")
public class UserController { @RequestMapping("getUserList")
public List<User> getUserList(){
User user1 = new User();
user1.setId(1);
user1.setUsername("loaderman1");
user1.setPassword("123");
User user2 = new User();
user2.setId(2);
user2.setUsername("loaderman2");
user2.setPassword("456");
User user3 = new User();
user3.setId(3);
user3.setUsername("loaderman3");
user3.setPassword("789");
List<User> list = new ArrayList<>();
list.add(user1);
list.add(user2);
list.add(user3);
return list;
}
}
测试
在浏览器访问 http://localhost:8080/user/getUserList
输出:
[{"id":1,"username":"loaderman1","password":"123"},{"id":2,"username":"loaderman2","password":"456"},{"id":3,"username":"loaderman3","password":"789"}]返回map测试
package com.generalichina.cimc.controller; import com.generalichina.cimc.bean.User;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController; import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map; /**
* Json返回数据的Controller
*/
@RestController
@RequestMapping("user")
public class UserController { @RequestMapping("getUserMap")
public Map<String,User> getUserMap(){
User user1 = new User();
user1.setId(1);
user1.setUsername("loaderman1");
user1.setPassword("123");
User user2 = new User();
user2.setId(2);
user2.setUsername("loaderman2");
user2.setPassword("456");
User user3 = new User();
user3.setId(3);
user3.setUsername("loaderman3");
user3.setPassword("789");
Map<String,User> map = new HashMap<>();
map.put("user1",user1);
map.put("user2",user2);
map.put("user3",user3);
return map;
}
}
{"user1":{"id":1,"username":"loaderman1","password":"123"},"user2":{"id":2,"username":"loaderman2","password":"456"},"user3":{"id":3,"username":"loaderman3","password":"789"}}