大家好，又见面了，我是你们的朋友全栈君。
1，
String output = FileUtils.ReadFile(url);
System.out.println(output);
JSONArray jsonArray = JSONObject.parseArray(output);
return jsonArray;2，String转成JSON的实现_javaQQ561487941的博客-CSDN博客_string转成json
String转成JSON
String json = “{“abc”:”1″,”hahah”:”2″}”;
JSONObject jsonObject = JSONObject.parseObject(content);
一句话就能解决，非常便捷。
想要取出值，可以对`jsonObject`进行操作：
jsonObject.getString(“abc”);
结果为：`1`
将String转为list后转为JSON
List<String> list = new ArrayList<String>();
list.add(“username”);
list.add(“age”);
list.add(“sex”);
JSONArray array = new JSONArray();
array.add(list);
将String转为map后转为JSON
Map<String, String> map = new HashMap<String, String>();
map.put(“abc”, “abc”);
map.put(“def”, “efg”);
JSONArray array_test = new JSONArray();
array_test.add(map);
JSONObject jsonObject = JSONObject.fromObject(map);
特别注意:从JSONObject中取值，碰到了数字为key的时候，如
{
“userAnswer”: {
“28568”: {
“28552”: {
“qId”: “28552”,
“order”: “1”,
“userScore”: {
“score”: 100
},
“answer”: {
“28554”: “28554”
},
“qScore”: “100.0”,
“qtype”: “SingleChoice”,
“sId”: “28568”
}
}
},
“paperType”: “1”,
“paperOid”: “28567”,
“instanceId”: 30823,
“remainingTime”: -1,
“examOid”: “28570”
}
获取“userAnswer”的value,再转成JSON,可仿照如下形式：
JSONObject userJson = JSONObject.parseObject(jsonObject.getString(“userAnswer”));
但是想获取key”28568″就没这么容易了。直接像上述的写法，会报错。
我们浏览fastjson中的源码，总结下，应该如下写：
JSONObject question = (JSONObject) JSONObject.parseObject(section.getString(“28568”), Object.class);
整体代码：
dao代码很容易，就不贴出来了。
package com.xiamenair.training.business.service;
import com.alibaba.fastjson.JSONObject;
import com.xiamenair.training.business.dao.elearningdao.ELearningExamInstanceDao;
import com.xiamenair.training.business.dao.masterdao.ELearningChoiceRecordDao;
import com.xiamenair.training.business.model.LasChoiceRecord;
import com.xiamenair.training.business.model.entity.elearning.LasExamInstance;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Service;
import java.math.BigDecimal;
import java.sql.Blob;
import java.sql.SQLException;
import java.text.SimpleDateFormat;
import java.util.*;
@Service
public class ChoiceRecordService {
//查询数据Dao
@Autowired
private ELearningChoiceRecordDao eLearningChoiceRecordDao;
//转储数据Dao
@Autowired
private ELearningExamInstanceDao eLearningExamInstanceDao;
private ChoiceRecordService() {
}
private static class SingletonRecordInstance {
private static final LasChoiceRecord choiceRecord = new LasChoiceRecord();
}
public static LasChoiceRecord getMapInstance() {
return SingletonRecordInstance.choiceRecord;
}
private static SimpleDateFormat simpleDateFormat = new SimpleDateFormat(“yyyy-MM-dd”);
/**
* 定时任务，每天定时将E学网考试数据分析并转储
*
* @param : instanceIdList
* @return : void
* @author : 28370·皮育才
* @date : 2018/11/20
**/
@Scheduled(cron = “00 00 01 * * ?”)
public void analysisChoiceRecord() {
//获取前一天的时间
Date date = new Date();
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
calendar.add(calendar.DATE, -1);
date = calendar.getTime();
String dateString = simpleDateFormat.format(date);
List<BigDecimal> instanceIdList = eLearningExamInstanceDao.findInstanceIdByFinishTime(dateString);
if(0 != instanceIdList.size()){
LasChoiceRecord lasChoiceRecord = getMapInstance();
instanceIdList.stream().forEach(instanceId -> {
Blob answerBlob = eLearningExamInstanceDao.findUserAnswer(instanceId);
Long userId = eLearningExamInstanceDao.findUserId(instanceId);
String content = null;
try {
content = new String(answerBlob.getBytes((long) 1, (int) answerBlob.length()));
} catch (SQLException e) {
e.printStackTrace();
System.out.println(“SQLEXCEPTION:” + e);
}
JSONObject jsonObject = JSONObject.parseObject(content);
//针对本section的”公共”属性直接设置
lasChoiceRecord.setUserId(userId);
lasChoiceRecord.setPaperType(jsonObject.getString(“paperType”));
lasChoiceRecord.setPaperId(jsonObject.getString(“paperOid”));
lasChoiceRecord.setExamInstanceId(jsonObject.getString(“instanceId”));
lasChoiceRecord.setRemainingTime(jsonObject.getString(“remainingTime”));
lasChoiceRecord.setExamId(jsonObject.getString(“examOid”));
//针对section中的题目进行细化循环拆分
JSONObject userJson = JSONObject.parseObject(jsonObject.getString(“userAnswer”));
Set sectionSet = userJson.keySet();
Iterator<String> setIt = sectionSet.iterator();
analyzeAnswer(lasChoiceRecord, userJson, setIt);
});
}
}
private void analyzeAnswer(LasChoiceRecord lasChoiceRecord, JSONObject userJson, Iterator<String> setIt) {
while (setIt.hasNext()) {
//对每个question进行再次拆分出题目
JSONObject section = (JSONObject) JSONObject.parseObject(userJson.getString(setIt.next()), Object.class);
Set questionSet = section.keySet();
Iterator<String> queIt = questionSet.iterator();
while (queIt.hasNext()) {
JSONObject question = (JSONObject) JSONObject.parseObject(section.getString(queIt.next()), Object.class);
String userAnswer = question.getString(“answer”);
String userScore = question.getString(“userScore”);
lasChoiceRecord.setQuestionId(question.getString(“qId”));
lasChoiceRecord.setRecordId(UUID.randomUUID().toString());
eLearningChoiceRecordDao.save(lasChoiceRecord);
}
}
}
}
———————
作者：JavaQQ群854630135
来源：CSDN
原文：https://blog.csdn.net/javaQQ561487941/article/details/84328669
版权声明：本文为博主原创文章，转载请附上博文链接！
不知道为啥
String json = “{“abc”:”1″,”hahah”:”2″}”;
JSONObject jsonObject = JSONObject.parseObject(content);
会一直抱错， object这个好像不行
7-1
今天遇到的这个问题，找了很多办法
最后这样解决的
src ：
[{“comcode”:”2143214″,”licenseno”:”粤·13″,”qqq”:”2131233123″,”startdate”:”2019-01-01″},
{“comcode”:”124124″,”licenseno”:”粤·1338″,”qqqq”:”1231233123123″,”startdate”:”2019-01-01″}]
JSONArray ja = JSONArray.parseArray(src); //把字符串转成json数组
String one = ja.getString(0); //取第一个元素
JSONObject jb123 = JSONObject.parseObject(one); //把这一个json串转成 json对象
System.out.println(“licenseno is ————— + jb123.get(“licenseno”)); //获取属性值
一开始写的是 把src直接传进到 parseObject 直接报错
com.alibaba.fastjson.JSONArray cannot be cast to com.alibaba.fastjson.JSONObject
debug进去 JSONObject 方法，慢慢发现，只能传一个{sadasdasd}这样的json格式的字段，不能传多个，[] 也不能有，尝试把src 的【】用replace 去掉，也不能去掉中间那个逗号
所以最后思路
把字符串转成 json格式的数据，然后再取了再传进去变成jsonobject
这样就能获取到一个json对象的对应属性 元素
所以啊 要多用 debug 多看底层源码 搞懂为啥
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