String 转Json：

 　　String str = "{\"age\":\"24\",\"name\":\"hekliu\"}";  
    JSONObject jsonObject = JSONObject.parseObject(str);
    System.out.println("json对象是：" + jsonObject);
    Object object = jsonObject.get("name");
    String  name= jsonObject.getString("name");

Json 转 String

    String str = "{\"age\":\"24\",\"name\":\"hekliu\"}";
    JSONObject jsonObject = JSONObject.parseObject(str);
    //json对象转字符串
    String jsonString = jsonObject.toJSONString();

3.String 转 Map

    String str = "{\"age\":\"24\",\"name\":\"hekliu\"}";
    JSONObject jsonObject = JSONObject.parseObject(str);
    //json对象转Map
    Map<String, Object> map = (Map<String, Object>)jsonObject;
    System.out.println("map对象是：" + map);
    Object object = map.get("age");

　

4.Map 转String

　　 Map<String,Object> map = new HashMap<>();
    map.put("age", 24);
    map.put("name", "hekliu");
    String jsonString = JSON.toJSONString(map);

 

5.Map 转 Json

    Map<String,Object> map = new HashMap<>();
    map.put("age", 24);
    map.put("name", "hekliu");
    JSONObject json = new JSONObject(map)

　　

6.Json 转 Map

 //json对象转Map
 Map<String, Object> map = (Map<String, Object>)jsonObject;