String转成JSON的实现

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>

1. 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`

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);   

1. 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);
            }
        }
    }
}