【Qt编程】基于Qt的词典开发系列<九>--JSON数据解析

在上一篇文章《用户登录及API调用的实现》中，我通过程序实现了用户登录及API调用的实现。从而能够实现网络查词、添词的操作。可是。从上文中能够看到。调用API后返回的是JSON格式的数据，例如以下图所看到的（在QtCreator中的显示）：

为了更好的观察JSON格式。我整理后显演示样例如以下：

显然。为了显示查词的结果，我们必须在上图中提取实用的信息，并正确的显示出来。

上图中每一行内容的意思我已经在文章《调用网络API》中作了解释。我在词典中选择想要显示的内容有：单词本身、单词ID、中文解释、英文解释、音标、发音音频。与之相应上图中的content、learning_id、definition、en_definitions、pron、audio。

为了获取这些内容，我们必须进行对上面的JSON格式数据（关于什么是JSON格式，能够自己百度）进行解析。在Qt 4中，没有相应的模块，必须单独增加相应的函数库，当然也能够自己依据JSON的格式自己敲代码提取你想要的内容，仅仅只是比較麻烦而已。在Qt5中。自带有相应的JSON解析模块。因此不用自己来写解析函数了，仅仅须要调用相应的函数。以下给出详细的程序实现：

程序的主体框架与文章《用户登录及API调用的实现》中的一样，仅仅是在当中增加了JSON数据解析功能。

详细的说，每当发送查词请求后，server就会返回JSON格式的单词内容。因此，我们仅仅须要在处理server返回数据的函数replyfinished（）函数中相应的查词操作QueryWordAction中进行JSON数据解析。将我们须要的内容存储到我们定义的Word类中。当中，word的定义例如以下：

因为仅仅是在上文《用户登录及API调用的实现》的程序中加了JSON解析的部分，其他部分基本没变。所以程序的执行流程及思路可见上文。当然，程序中的凝视也算比較详细。因此不作详细说明。仅仅须要将以下五个源文件放入空的Qt项目中就可以。注意：是在Qt 5中，且须要在其.pro文件里增加语句：QT +=core gui network webkit multimedia。

详细的源文件例如以下：

1、word.h文件

#ifndef WORD_H
#define WORD_H
#include
#include
#include 
#include
#include
class Word
{
public:
    explicit Word();
    Word(const Word& word);
    ~Word();
public:

    QString name;//单词本身
    QString learning_id;//单词ID
    QString definition;//单词中文解释
    QString en_definitions;//单词英文解释
    QString pron;//单词音标
    QString audio;//单词的发音音频

    void clear();
};

#endif // WORD_H

2、word.cpp文件

#include "word.h"

Word::Word()
{

}
Word::Word(const Word &w)
{
    name=w.name;
    learning_id=w.learning_id;
    definition=w.definition;
    en_definitions=w.en_definitions;
    pron=w.pron;
    audio=w.audio;

}

Word::~Word()
{
}




void Word::clear()//清除内容
{
    name="";
    learning_id="";
    definition="";
    en_definitions="";
    pron="";
    audio="";
   // this->examples=NULL;
}

3、network.h文件

#ifndef NETWORK_H
#define NETWORK_H
#include"word.h"

#include 
#include 
#include
#include
#include
#include
#include 
#include 
#include 
#include 
#include
#include
#include
#include
#include

class netWork : public QObject
{
    Q_OBJECT
public:
    explicit netWork(QObject *parent = 0);
 //   ~netWork();


    enum HttpAction{NoAction,NetStudy,GetSessionidAction,LoginAction,QueryWordAction,AddWordAction,AddExampleAction,QueryWordExamplesAction};
    HttpAction httpAction;
    QNetworkAccessManager * http;
    QString sessionid;
    QString queryword;//要查询的单词
    QString nickname;
    QString username;
    QString password;
    bool isBusy;

    Word *gotword;//通过訪问网络得到的单词信息
    QString getCookie(const QString &name);

    void loginShanbay();
    void queryWord(const QString &word);
    void queryExamples(QString learningid);
    void connectNet(QString username="nineheadedbird", QString password="123456");
    void addWord(const QString &word);

signals:

    void signalQueryFinished(Word *word);
    void connectSuccess();
    void connectFail();
    void verifySuccess();
    void verifyFail();
    void NetState(bool);
public slots:
    void replyfinished(QNetworkReply*);

};

#endif // NETWORK_H

4、network.cpp文件

#include "network.h"
#include
#include
netWork::netWork(QObject *parent) :
    QObject(parent)
{
        http=new QNetworkAccessManager(this);
        http->setCookieJar(new QNetworkCookieJar(this));
        connect(http,SIGNAL(finished(QNetworkReply*)),this,SLOT(replyfinished(QNetworkReply*)));
        isBusy=true;
        gotword=new Word();

}

QString netWork::getCookie(const QString &name)
{
    foreach(QNetworkCookie cookie , http->cookieJar()->cookiesForUrl(QUrl("http://www.shanbay.com/")))
    {
            //qDebug()cookie.name();
            if(cookie.name()==name)
            {
                return cookie.value();
            }
        }
        return "";
}


void netWork::loginShanbay()
{
       QNetworkRequest request;
       request.setUrl(QUrl("http://www.shanbay.com/accounts/login/"));
       request.setRawHeader("Accept","text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8");
       request.setRawHeader("Accept-Charset","GBK,utf-8;q=0.7,*;q=0.3");
       request.setRawHeader("Accept-Language","zh-CN,zh;q=0.8");
       request.setRawHeader("Cache-Control","max-age=0");
       request.setRawHeader("Connection","keep-alive");
       request.setRawHeader("Host","www.shanbay.com");
       request.setRawHeader("User-Agent","Mozilla/5.0 (Windows NT 6.1) AppleWebKit/535.7 (KHTML, like Gecko) Chrome/16.0.912.63 Safari/535.7");
       request.setRawHeader("Origin","http//www.shanbay.com");
       request.setRawHeader("Referer","http://www.shanbay.com/accounts/login/");
       request.setRawHeader("Host","www.shanbay.com");
       request.setRawHeader("Content-Type","application/x-www-form-urlencoded");
       QByteArray postData;
       postData.append(QString("csrfmiddlewaretoken=%1&").arg(sessionid));
       postData.append(QString("username=%1&password=%2&").arg(QUrl::toPercentEncoding(username).constData()).arg(password));
       postData.append("login=登录&continue=home&u=1&next=");
       request.setHeader(QNetworkRequest::ContentLengthHeader,postData.size());
       httpAction=LoginAction;
       http->post(request,postData);
}

void netWork::queryWord(const QString &word)
{
      QNetworkRequest request;
      request.setUrl(QUrl("http://www.shanbay.com/api/word/"+word));
      request.setRawHeader("Accept","text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8");
      request.setRawHeader("Accept-Charset","GBK,utf-8;q=0.7,*;q=0.3");
      request.setRawHeader("Accept-Language","zh-CN,zh;q=0.8");
      request.setRawHeader("Cache-Control","max-age=0");
      request.setRawHeader("Connection","keep-alive");
      request.setRawHeader("Host","www.shanbay.com");
      request.setRawHeader("User-Agent","Mozilla/5.0 (Windows NT 6.1) AppleWebKit/535.7 (KHTML, like Gecko) Chrome/16.0.912.63 Safari/535.7");
      httpAction=QueryWordAction;
      http->get(request);
}

void netWork::queryExamples(QString learningid)
{
    if(learningid=="0"){
           return;
       }
       QNetworkRequest request;
       request.setUrl(QUrl("http://www.shanbay.com/api/learning/examples/"+learningid));
       request.setRawHeader("Accept","text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8");
       request.setRawHeader("Accept-Charset","GBK,utf-8;q=0.7,*;q=0.3");
       request.setRawHeader("Accept-Language","zh-CN,zh;q=0.8");
       request.setRawHeader("Cache-Control","max-age=0");
       request.setRawHeader("Connection","keep-alive");
       request.setRawHeader("Host","www.shanbay.com");
       request.setRawHeader("User-Agent","Mozilla/5.0 (Windows NT 6.1) AppleWebKit/535.7 (KHTML, like Gecko) Chrome/16.0.912.63 Safari/535.7");
       httpAction=QueryWordExamplesAction;
       http->get(request);
}


void netWork::addWord(const QString &word)
{
    if(word.isEmpty())
        qDebug()"你的输入有误";
    else
    {
        QNetworkRequest request;
        request.setUrl(QUrl("http://www.shanbay.com/api/learning/add/"+word));
        request.setRawHeader("Accept","text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8");
        request.setRawHeader("Accept-Charset","GBK,utf-8;q=0.7,*;q=0.3");
        request.setRawHeader("Accept-Language","zh-CN,zh;q=0.8");
        request.setRawHeader("Cache-Control","max-age=0");
        request.setRawHeader("Connection","keep-alive");
        request.setRawHeader("Host","www.shanbay.com");
        request.setRawHeader("User-Agent","Mozilla/5.0 (Windows NT 6.1) AppleWebKit/535.7 (KHTML, like Gecko) Chrome/16.0.912.63 Safari/535.7");
        httpAction=AddWordAction;
        http->get(request);
    }
}

void netWork::connectNet(QString username, QString password)
{
        this->username=username;
        this->password=password;
         QNetworkRequest request;
        request.setUrl(QUrl("http://www.shanbay.com/accounts/login/"));
        request.setRawHeader("Accept","text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8");
        request.setRawHeader("Accept-Charset","GBK,utf-8;q=0.7,*;q=0.3");
        request.setRawHeader("Accept-Language","zh-CN,zh;q=0.8");
        request.setRawHeader("Cache-Control","max-age=0");
        request.setRawHeader("Connection","keep-alive");
        request.setRawHeader("Host","www.shanbay.com");
        request.setRawHeader("User-Agent","Mozilla/5.0 (Windows NT 6.1) AppleWebKit/535.7 (KHTML, like Gecko) Chrome/16.0.912.63 Safari/535.7");
        httpAction=GetSessionidAction;
        http->get(request);
}

void netWork::replyfinished(QNetworkReply *reply)
{
    QByteArray wordInformation;
    QVariant status_code=reply->attribute(QNetworkRequest::HttpStatusCodeAttribute);
 //  qDebug()"code_state="if(status_code==QVariant::Invalid)
        emit NetState(false);
    else
        emit NetState(true);
    QJsonDocument jsonDoc;
    QJsonObject jsonObj,vocObj,en_definitionsObj;

    switch(httpAction)
    {
    case NoAction:
        break;
    case GetSessionidAction:
        sessionid=getCookie("csrftoken");
        if(!sessionid.isEmpty()){
            emit connectSuccess();

            qDebug()"Connect successfully! Verifying username and password...");
           loginShanbay();
        }else{
            emit connectFail();

             qDebug()"Cannot connect! Please try to check the internet!");
        }

        break;
    case LoginAction:
        httpAction=NoAction;
        if(0==reply->readAll().size())
        {
            QString nickname=QUrl::fromPercentEncoding(getCookie("username").toLatin1());
            emit verifySuccess();

            qDebug()"Login successfully!""hello");
        }else
        {
            emit verifyFail();
            qDebug()"Failed to login! Please check!";
        }
        break;
    case QueryWordAction://是在这里面进行JSON数据解析!
        qDebug()"----query word----";

        wordInformation=reply->readAll();
         qDebug()"the information of word in JSON format::\n";
         qDebug()QJsonDocument::fromJson( wordInformation);
        if(!jsonDoc.isNull())
        {
            jsonObj=jsonDoc.object();
            vocObj=jsonObj.value("voc").toObject();//Qt5 自带JSON解析，因此非常easy得到单词的各个部分的内容
            en_definitionsObj=vocObj.value("en_definitions").toObject();   
            gotword->clear();

            gotword->name=vocObj.value("content").toString();//单词本身

            gotword->learning_id=QString::number(jsonObj.value("learning_id").toDouble(),‘g‘,15);
            gotword->definition=vocObj.value("definition").toString();//中文解释
            gotword->pron=vocObj.value("pron").toString();//单词音标


            gotword->pron=gotword->pron;
            gotword->audio=vocObj.value("audio").toString();

            //因为单词的英文解释有多项（词性、解释等等）。我们将结果用html格式表示。并使得词性颜色设置为黑色
            for( QJsonObject::const_iterator it=en_definitionsObj.constBegin();it!=en_definitionsObj.constEnd();it++)
            {
                gotword->en_definitions+=QString("
%1. ").arg(it.key());
                if(it.value().isArray())
                {
                    foreach(QJsonValue jv,it.value().toArray())
                    {
                       gotword->en_definitions+=QString("%1; ").arg(jv.toString());
                    }
                }
                gotword->en_definitions+="
";

            }

            emit signalQueryFinished(gotword);
           //显示JSON解析后的数据
            qDebug()"name="name;
            qDebug()"word="learning_id;
            qDebug()"definition="definition;
            qDebug()"en_definitions="en_definitions;
            qDebug()"pron="pron;
            qDebug()"audio"audio;

            //进行网络发音
            QMediaPlayer *player = new QMediaPlayer();
                player->setMedia(QUrl(gotword->audio));
                player->play();
            if(gotword->learning_id!="0")//不是新单词
            {

                qDebug()"你学过这个单词";
            }

        }

        break;

    case QueryWordExamplesAction:
//            qDebug()"query word examples";
//             qDebug()readAll();

            break;

    case AddWordAction:
//        qDebug()"add word";
        jsonDoc=QJsonDocument::fromJson(reply->readAll());
        if(!jsonDoc.isNull())
        {
            jsonObj=jsonDoc.object();
            //qDebug()"jsonObj"learning_id=QString::number(jsonObj.value("id").toDouble(),‘g‘,15);
          //  qDebug()"id").toDouble()"add word result learning id="learning_idlearning_id!="0");
         //   emit signalAddwordFinished(DICT::word->learning_id!="0");
         //   queryExamples(DICT::word->learning_id);
        }



    default:break;
    }
}

5、main.cpp文件

#include 
#include "network.h"

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    netWork *nW = new netWork();
    nW->connectNet();

    return a.exec();
}

执行结果例如以下图：

基于Qt的词典开发系列

1. 词典框架设计及成品展示
2. 本地词典的设计
3. 開始菜单的设计
4. 无边框窗体的缩放与拖动
5. 无边框窗体的拖动
6. 界面美化设计
7. 调用网络API
8. 用户登录及API调用的实现
9. JSON数据解析
10. 国际音标的显示
11. 系统托盘的显示
12. 调用讲述人
13. 音频播放
14. 自己主动补全功能
15. HTML特殊字符及正則表達式
16. 后序

作品下载地址（公布版）：http://download.csdn.net/detail/tengweitw/8548767
作品下载地址（绿色版）：http://download.csdn.net/detail/tengweitw/8830495
源代码下载地址：http://download.csdn.net/detail/tengweitw/8830503

原文：http://blog.csdn.net/tengweitw/article/details/46506945
作者：nineheadedbird