主要处理tcp的json数据流,解析和除错json数据流,继承与 qtcpsocket层,方便扩展

数据流格式:

#ifndef CONFIGTCPSOCKET_H
#define CONFIGTCPSOCKET_H

#include <QTcpSocket>
#include <QJsonDocument>

class JsonTcpSocket : public QTcpSocket
{
  Q_OBJECT
public:
  explicit JsonTcpSocket(QObject *parent = 0);
  virtual ~JsonTcpSocket();
  const QString &getLastError()const{return lastErrorString;}
  const int &getLastCode()const{return lastErrorCode;}


public slots:
  bool write(const char *json);
  bool write(const QJsonDocument &json);
  bool write(const QByteArray &json);
  bool write(const QString &json);
  bool write(const QJsonObject &obj);

signals:
  void newJsonData(const QJsonDocument &doc);//新的json数据
  void jsonError(const int &errorCode,const QString &errorString);//json格式错误
  void socketError(const int &errorCode,const QString &errorString);//网络错误

private slots:
  void readBytes();//读取字节
  void networkError(QAbstractSocket::SocketError error);//网络错误

private:
  int readByteCount=0;

  QString lastErrorString; //最后的错误文字
  int lastErrorCode;//错误代码

};

#endif // CONFIGTCPSOCKET_H

#include "jsontcpsocket.h"
#include <QDataStream>
#include "settingconfig.h"
#include <QByteArray>
#include <QThread>
#include "commonfunction.h"

JsonTcpSocket::JsonTcpSocket(QObject *parent) :
  QTcpSocket(parent)
{

  connect(this,&JsonTcpSocket::readyRead,this,&JsonTcpSocket::readBytes);

  connect(this,SIGNAL(error(QAbstractSocket::SocketError)),this,SLOT(networkError(QAbstractSocket::SocketError)));

  this->setSocketOption(QAbstractSocket::LowDelayOption,"1"); //启用nagle低延迟算法
  this->setSocketOption(QAbstractSocket::KeepAliveOption,"1"); //设置保持连接状态

}

JsonTcpSocket::~JsonTcpSocket()
{

}

void JsonTcpSocket::readBytes()//读取字节
{
  if(this->readByteCount==0)
    {
      char peek;
      this->read(&peek,sizeof(peek));

      if(peek==‘l‘)   //查看是否是数据包的起始位置
        {
          char len[READ_RAW_LEN];//读取json数据的长度

          this->read(len,sizeof(len));

          ByteToInt(len,&this->readByteCount);

        }else  //否则就丢弃全部的数据
        {
          this->readAll();
          //qDebug()<<"read all data:"<<this->readAll();
          return;
        }
    }

  if(this->readByteCount>this->bytesAvailable())
    return;

  char *json=new char[this->readByteCount];

  this->read(json,this->readByteCount);  //读取json数据

  this->readByteCount=0; //数据长度重设为0;

  QJsonParseError parseError;
  QJsonDocument jsonDoc(QJsonDocument::fromJson(json,&parseError));

  if(parseError.error==QJsonParseError::NoError)  //json格式是否正确
    {
      // qDebug()<<"read json data:"<<jsonDoc.toJson();
        emit newJsonData(jsonDoc); //发送json数据信号
    }
  else
    {
        this->lastErrorCode=parseError.error;
        this->lastErrorString=parseError.errorString();
        emit jsonError(parseError.error,parseError.errorString()); //发送错误代码
        qDebug()<<"json format error:"<<json;
    }


  delete []json;

  this->readBytes(); //继续读取一下段数据
}


bool JsonTcpSocket::write(const char *json)
{
  return this->write(QJsonDocument::fromJson(json));
}

bool JsonTcpSocket::write(const QByteArray &json)
{
  return this->write(QJsonDocument::fromJson(json));
}

bool JsonTcpSocket::write(const QString &json)
{
  return this->write(QJsonDocument::fromVariant(json));
}

bool JsonTcpSocket::write(const QJsonObject &obj)
{
  return this->write(QJsonDocument(obj));
}

bool JsonTcpSocket::write(const QJsonDocument &json)
{

  QByteArray array;
  array.prepend(json.toJson(QJsonDocument::Compact));

  int len=array.length();
  char lenByte[READ_RAW_LEN];

  IntToByte(len,lenByte);

  array.prepend(lenByte,sizeof(lenByte));

  array.prepend(‘l‘);

  int bytes=-1;

  bytes=QTcpSocket::write(array);

  return bytes!=-1;
}


void JsonTcpSocket::networkError(QAbstractSocket::SocketError error)//网络错误
{
    this->lastErrorString=this->errorString();
    this->lastErrorCode=error;
    emit socketError(error,this->lastErrorString);
}