json字符串转list对象

分手后的思念是犯贱 2023-07-10 12:59 25阅读 0赞

package com.kry.xr.Test;
    
    import com.alibaba.fastjson.JSONArray;
    import com.alibaba.fastjson.JSONObject;
    import com.eebbk.pointreadOnline.app.util.JsonUtils;
    import com.fasterxml.jackson.core.JsonParser;
    import com.fasterxml.jackson.databind.ObjectMapper;
    import com.fasterxml.jackson.databind.type.CollectionType;
    import com.kry.xr.entity.UserLog;
    
    import java.io.IOException;
    import java.util.ArrayList;
    import java.util.List;
    
    public class Json {
    
    
        public static void main(String[] args) {
            String resultData=  "[{\"userid\":19,\"username\":5,\"state\":9},{\"userid\":20,\"username\":6,\"state\":9}]";
            String resultData1=     "[{\"userid\":19,\"username\":5},{\"userid\":20,\"username\":6}]";
           // JSONObject jsonObject=JSONObject.parseObject(resultData);
            string 转list
            //1
            JSONArray list =(JSONArray)JSONArray.parseArray(resultData);
            List<UserLog> list1 = JSONObject.parseArray(list.toJSONString(), UserLog.class);
            //2
            JSONArray list2 =(JSONArray)JSONArray.parseArray(resultData1);
            List<UserLogTest> list3 = JSONObject.parseArray(list2.toJSONString(), UserLogTest.class);
            //3     
         List<UserLog> UserLogList = jsonStr2List(resultData1, UserLog.class);
         Integer ap=1;
        //list转string
        String resultString=obj2JsonStr(UserLogList);

System.out.println(resultString);
        }
        public static <T> List<T> jsonStr2List(String jsonStr, Class<T> elementClass)
        {
            List<T> resultList = null;
    
            ObjectMapper objectMapper = new ObjectMapper();
    
            CollectionType collectionType = objectMapper.getTypeFactory().constructCollectionType(ArrayList.class,
                    elementClass);
    
            try
            {
                resultList = objectMapper.readValue(jsonStr, collectionType);
            }
            catch (RuntimeException e)
            {
                System.out.println("json字符串转List对象发生异常！"+ e);
            }
    
            catch (IOException e)
            {
                System.out.println("json字符串转List对象发生异常！"+ e);
            }
    
            return resultList;
        }
        public static String obj2JsonStr(Object obj)
        {
            ObjectMapper objectMapper = new ObjectMapper();
    
            String result = null;
    
            try
            {
                // 允许反斜杆等字符
                objectMapper.configure(JsonParser.Feature.ALLOW_UNQUOTED_CONTROL_CHARS, true);
    
                // 允许单引号
                objectMapper.configure(JsonParser.Feature.ALLOW_SINGLE_QUOTES, true);
    
                result = objectMapper.writeValueAsString(obj);
            }
            catch (IOException e)
            {
                System.out.println("java对象转json字符串发生异常！"+e);
            }
            return result;
        }
    }

-----------------------使用@Data
    import lombok.Builder;
    import lombok.Data;
    import lombok.experimental.Accessors;
    @Data
    @Accessors(chain = true)
    @Builder
    public class UserLog {
        private String username;
        private String userid;
        private String state;
        public  UserLog(String username,String userid,String state){
            this.username=username;
            this.userid=userid;
            this.state=state;
        }
        public  UserLog(){
        }
    }