一、json格式字符串转json对象。

    1、json对象字符串:

String jsonStr = "{'code':1,'msg':'success'}";
JSONObject.fromObject(jsonStr); //{"code":1,"msg":"success"}
jsonObject.getString("msg"); //success

    2、json数组字符串:

String jsonArr = "[{'code':0,'msg':'fail'},{'code':1,'msg':'success'}]";
JSONArray.fromObject(jsonArr);

        遍历取值...

二、json对象转实体类

1.定义实体类:

public class Entity { 

    private String code; 

    private String msg; 


    public String getCode() { 

        return code; 

    } 

    public void setCode(String code) { 

        this.code = code; 

    } 

    public String getMsg() { 

        return msg; 

    } 

    public void setMsg(String msg) { 

        this.msg = msg; 

    } 

}

2.用toBean()方法转化为实体类。

Entity jsonDemo = (Entity) JSONObject.toBean(jsonObject,Entity.class);

三、json和list互转

1.json转list

String jsonArr = "[{'code':0,'msg':'fail'},{'code':1,'msg':'success'}]";
JSONArray jsonArray = JSONArray.fromObject(jsonArr); 

List<Entity> list = JSONArray.toList(jsonArray,Entity.class);

2.list转json

JSONArray listArray=JSONArray.fromObject(lists);