javabean转json (利用第三方jar包)

利用反射机制，将实体类中的属性进行反射为json形式的数据

导入第三方jar包 (http://pan.baidu.com/s/1o88tHjG)

编写一个实体类:City.java

package com.mo.bean2json;

public class City {
  private int id;
  private String name;
  
  public City(int id, String name) {
    super();
    this.id = id;
    this.name = name;
  }
  
}

编写测试类；

·将一个实体类转换为json数据

@Test
  public void bean2json(){
    City city = new City(1,"广州");
    JSONArray jsonArray = JSONArray.fromObject(city);
    System.out.println(jsonArray);
    //[{"id":1,"name":"广州"}]
  }

·将一个list转换为json数据

@Test
  public void list2json(){
    List<City> list = new ArrayList<City>();
    list.add(new City(1,"广州"));
    list.add(new City(2,"珠海"));
    list.add(new City(3,"深圳"));
    JSONArray jsonArray = JSONArray.fromObject(list);
    System.out.println(jsonArray);
    //[{"id":1,"name":"广州"},{"id":2,"name":"珠海"},{"id":3,"name":"深圳"}]
  }

·将一个存在list的bean转换为json

编写一个bean

package com.mo.bean2json;

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

public class Province {
  private int id;
  private String name;
  private List<City> cityList = new ArrayList<City>();//这里的set get方法省略

}

测试类

@Test
  public void beanlist2json(){
    List<City> list = new ArrayList<City>();
    list.add(new City(1,"广州"));
    list.add(new City(2,"珠海"));
    Province province = new Province(1,"广东",list);
    JSONArray jsonArray = JSONArray.fromObject(province);
    System.out.println(jsonArray);
    /*[
      {
        "id":1,
        "cityList":[{"id":1,"name":"广州"},{"id":2,"name":"珠海"}],
        "name":"广东"
      }
      ]*/
  }

·map转json

@Test
  public void map2json(){
    List<City> list = new ArrayList<City>();
    list.add(new City(1,"广州"));
    list.add(new City(2,"珠海"));
    
    Map<String,Object> map = new LinkedHashMap<String,Object>();
    map.put("total",list.size());
    map.put("rows",list);
    
    JSONArray fromObject = JSONArray.fromObject(map);
    System.out.println(fromObject);
    /*[
     {
       "total":2,
       "rows":[{"id":1,"name":"广州"},{"id":2,"name":"珠海"}]
     }
     ]*/
    
    //去掉外面的中括号
    String jsonJAVA = fromObject.toString();
    String substring = jsonJAVA.substring(1, jsonJAVA.length()-1);
    System.out.println(substring);
    /*{
      "total":2,
      "rows":[{"id":1,"name":"广州"},{"id":2,"name":"珠海"}]
    }*/
  }