SpringBoot之返回json数据的实现方法

一、创建一个springBoot个项目

操作详情参考：1.SpringBoo之Helloword 快速搭建一个web项目

二、编写实体类

/**
 * Created by CR7 on 2017-8-18 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;

/**
 * Created by CR7 on 2017-8-18 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("zhanghaoliang");
    user.setPassword("1231");
    return user;
  }
}

四、测试返回Json数据

浏览器输入http://localhost:8080/user/getUser

得出结果：服务器是以json数据格式返回给浏览器

五、返回list到页面

5.1.返回数据的controller

package com.example.demo;

import com.example.bean.User;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.ArrayList;
import java.util.List;

/**
 * Created by CR7 on 2017-8-18 Json返回数据的Controller
 */
@RestController
@RequestMapping("user")
public class ReturnJsoncontroller {
  
  @RequestMapping("getUserList")
  public List<User> getUserList(){
    User user1 = new User();
    user1.setId(1);
    user1.setUsername("zhanghaoliang");
    user1.setPassword("123");
    User user2 = new User();
    user2.setId(2);
    user2.setUsername("chensi");
    user2.setPassword("456");
    User user3 = new User();
    user3.setId(3);
    user3.setUsername("doudou");
    user3.setPassword("789");
    List<User> list = new ArrayList<>();
    list.add(user1);
    list.add(user2);
    list.add(user3);
    return list;
  }
}

5.2.得出结果

在浏览器访问 http://localhost:8080/user/getUserList

六、返回map到浏览器

既然返回实体，和list的试验过了，那么再试验一下返回Map类型的数据吧

6.1返回的Controller

package com.example.demo;

import com.example.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;

/**
 * Created by CR7 on 2017-8-18 Json返回数据的Controller
 */
@RestController
@RequestMapping("user")
public class ReturnJsoncontroller {

  @RequestMapping("getUserMap")
  public Map<String,User> getUserMap(){
    User user1 = new User();
    user1.setId(1);
    user1.setUsername("zhanghaoliang");
    user1.setPassword("123");
    User user2 = new User();
    user2.setId(2);
    user2.setUsername("chensi");
    user2.setPassword("456");
    User user3 = new User();
    user3.setId(3);
    user3.setUsername("doudou");
    user3.setPassword("789");
    Map<String,User> map = new HashMap<>();
    map.put("user1",user1);
    map.put("user2",user2);
    map.put("user3",user3);
    return map;
  }
}

6.2得出的结果

在浏览器中访问http://localhost:8080/user/getUserMap