依赖fastjson

一、String

1.String转JSONObject

JSONObject jsonObject = JSON.parseObject（String）

2.String转JSONArray

JSONArray jsonArray = JSONArray.parseArray(String)

  1. String jsonMessage = "[{\"语文\":\"88\"},{\"数学\":\"78\"},{\"计算机\":\"98\"}]";
  2. JSONArray jsonArray = JSONArray.parseArray(jsonMessage);
  5. [{"语文":"88"},{"数学":"78"},{"计算机":"98"}]

3.String转Object

Obj obj = JSONObject.parseObject(String,Obj.class)

  1.         People people = new People();
  2.         people.setName("张三");
  3.         people.setAge(15);
  4.         people.setHeight(12.5F);
  5.         people.setDesc("法外狂徒");
  7.         String string = JSONObject.toJSONString(people);
  9.         People people1 = JSONObject.parseObject(string, People.class);

4.String转List

  • 格式为 “1,2,3”;
  • 格式为 [{“uid”:“1”,“userName”:“小明”},{“uid”:“2”,“userName”:“小红”}]

格式一：String uid=”1,2,3”;
①转为List uids={1,2,3}

  1. List<Long> uids=Arrays.stream(uid.split(",")).map(s->Long.parseLong(s.trim())).collect(Collectors.toList())

②转为List uids={“1”,”2”,”3”}

  1. List<String> uids=Arrays.asList(uid.split(","));

格式二：String user=”[{\”uid\”:\”1\”,\”userName\”:\”小明\”},{\”uid\”:\”2\”,\”userName\”:\”小红\”}]”;
转为List

  1. List<User> userList=JSONArray.parseArray(user,User.class);

5.String转Map

①split(“,”),遍历再split(“:”) map.put()

  1. public static Map<String, String> getStringToMap(String str) {
  2.         // 判断str是否有值
  3.         if (null == str || "".equals(str)) {
  4.             return null;
  5.         }
  6.         // 根据&截取
  7.         String[] strings = str.split(",");
  8.         // 设置HashMap长度
  9.         int mapLength = strings.length;
  10.         Map<String, String> map = new HashMap<>(mapLength);
  11.         // 循环加入map集合
  12.         for (String string : strings) {
  13.             // 截取一组字符串
  14.             String[] strArray = string.split(":");
  15.             // strArray[0]为KEY strArray[1]为值
  16.             map.put(strArray[0], strArray[1]);
  17.         }
  18.         return map;
  19.     }

②转jsonObject，遍历jsonObject，相当于两个map操作;

  2.  JSONObject user = resJson.getJSONObject("user");
  3.  Map<String, Object> userMap = new HashMap<>();       
  4. //循环转换                
  5. for (Map.Entry<String, Object> entry : user.entrySet()) {                    
  6.     userMap.put(entry.getKey(), entry.getValue());                
  7. }

二、JSONObject

1.jsonObject转