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

com.alibabafastjson1.2.15

String转成JSON

Stringjson ="{\"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

Listlist=newArrayList();list.add("username");list.add("age");list.add("sex");  JSONArrayarray=newJSONArray();array.add(list);

将String转为map后转为JSON

Mapmap=newHashMap();map.put("abc","abc");map.put("def","efg");JSONArray array_test =newJSONArray();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：

JSONObjectuserJson = 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。packagecom.xiamenair.training.business.service;importcom.alibaba.fastjson.JSONObject;importcom.xiamenair.training.business.dao.elearningdao.ELearningExamInstanceDao;importcom.xiamenair.training.business.dao.masterdao.ELearningChoiceRecordDao;importcom.xiamenair.training.business.model.LasChoiceRecord;importcom.xiamenair.training.business.model.entity.elearning.LasExamInstance;importorg.springframework.beans.factory.annotation.Autowired;importorg.springframework.scheduling.annotation.Scheduled;importorg.springframework.stereotype.Service;importjava.math.BigDecimal;importjava.sql.Blob;importjava.sql.SQLException;importjava.text.SimpleDateFormat;importjava.util.*;@ServicepublicclassChoiceRecordService{//查询数据Dao@AutowiredprivateELearningChoiceRecordDao eLearningChoiceRecordDao;//转储数据Dao@AutowiredprivateELearningExamInstanceDao eLearningExamInstanceDao;privateChoiceRecordService(){    }privatestaticclassSingletonRecordInstance{privatestaticfinalLasChoiceRecord choiceRecord =newLasChoiceRecord();    }publicstaticLasChoiceRecordgetMapInstance(){returnSingletonRecordInstance.choiceRecord;    }privatestaticSimpleDateFormat simpleDateFormat =newSimpleDateFormat("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 * * ?")publicvoidanalysisChoiceRecord(){//获取前一天的时间Date date =newDate();        Calendar calendar = Calendar.getInstance();        calendar.setTime(date);        calendar.add(calendar.DATE, -1);        date = calendar.getTime();        String dateString = simpleDateFormat.format(date);        List 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 =newString(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 setIt = sectionSet.iterator();                analyzeAnswer(lasChoiceRecord, userJson, setIt);            });        }    }privatevoidanalyzeAnswer(LasChoiceRecord lasChoiceRecord, JSONObject userJson, Iterator 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 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);            }