String转成JSON
这个依赖很重要，我们将围绕fastjson中的JSONObject这个类来谈转换
???<dependency> ???????<groupId>com.alibaba</groupId> ???????<artifactId>fastjson</artifactId> ???????<version>1.2.15</version> ???</dependency>- 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.*;@Servicepublic 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); ???????????} ???????} ???}}String转成JSON的实现
原文地址：https://www.cnblogs.com/pipicai96/p/9986181.html