String和JSON相互转换

1.JSON格式的字符串转对象

import com.alibaba.fastjson.JSONObject;
import com.alibaba.fastjson.TypeReference;
//String转对象
String message = "{\"name\":\"John\", \"age\":30, \"city\":\"New York\"}";
Person freeData = JSONObject.parseObject(message, new TypeReference<Person>(){});

2.对象转Json格式的字符串

JSON.toJSONString(faceStructuredData)

3.对象转JSONObject

//目标参数
JSONObject.parseObject(JSON.toJSONString(personNode));

4.将 json格式的字符串 转换 为JSONArray：

        方法一:

String str = "[{\"name\":\"Alice\",\"age\":20},{\"name\":\"Bob\",\"age\":30}]";
JSONArray jsonArray = JSON.parseArray(str);

         方法二:

String jsonString = "[\"value1\",\"value2\"]";
JSONArray jsonArray = new JSONArray(jsonString);

5.将JSONArray转换为 json格式的字符串：

         方法一:

JSONArray jsonArray = new JSONArray();
JSONObject obj1 = new JSONObject();
obj1.put("name", "Alice");
obj1.put("age", 20);
JSONObject obj2 = new JSONObject();
obj2.put("name", "Bob");
obj2.put("age", 30);
jsonArray.add(obj1);
jsonArray.add(obj2);
String str = jsonArray.toJSONString();

        方法二:

JSONArray jsonArray = new JSONArray();
jsonArray.put("value1");
jsonArray.put("value2");
String jsonString = jsonArray.toString();

6. 对象集合转JSONArray

//对象集合转JSONArray 
List<Station> stations = List.of(new Station("北京站", "BJS"),new Station("上海站", "SHH"));
JSONArray jsonArray = JSONArray.parseArray(JSON.toJSONString(stations));

7.JSONObject和字符串的转换

import com.alibaba.fastjson.JSONObject;
#存入属性
JSONObject jsonObject = new JSONObject();
jsonObject.put("name", "John");
jsonObject.put("age", 30);
String myStr = jsonObject.toJSONString();
#取出属性
JSONObject jsonObject1 = JSON.parseObject(myStr);
String name = jsonObject1.getString("name");

8.list和map转json格式的字符串

import com.alibaba.fastjson.JSON;
//list和map转json格式的字符串
 List<Map<String,Object>> referTeamTradeTopList = new ArrayList<>();
 HashMap<String, Object> map = new HashMap<>();
 map.put("realname","zhangs");
 map.put("productName","haike");
 map.put("totalAmount",12);
 referTeamTradeTopList.add(map);
//打印
 String s1 = JSON.toJSONString(map);
 //s1: {"totalAmount":12,"productName":"haike","realname":"zhangs"}
 String s2 = JSON.toJSONString(referTeamTradeTopList);
 //s2: [{"totalAmount":12,"productName":"haike","realname":"zhangs"}]