不浮躁
分类: WINDOWS
2015-04-21 21:07:10
原文地址:QT编写多线程TCP文件接收服务器 作者:进击的菜鸟
目标:
用户端程序,用标准的socket完成文件传输的功能,代码如下:
1: // Linux下网络编程,客户端程序代码
2: //程序运行参数:
3: // ./client IPADDRESS PORTNUMBER
4: // (其中IPADDRESS是服务端IP地址,PORTNUMBER是服务端用于监听的端口)
5: //
6:
7: #include
8: #include
9: #include
10: #include
11: #include
12: #include
13: #include
14: #include
15: #include
16: #include
17: #include
18:
19:
20: //用这个my_read()函数代替本来的read()函数原因有以下几点:
21: //
22: //ssize_t read(int fd,void *buf,size_t nbyte)
23: //read函数是负责从fd中读取内容。当读成功时,read返回实际所读的字节数;如果
24: //返回的值是0,表示已经读到文件的结束了;小于0表示出现了错误。
25: //
26: // 1)如果错误为EINTR说明read出错是由中断引起的,继续读。
27: // 2)如果是ECONNREST表示网络连接出了问题,停止读取。
28:
29: size_t min(size_t a,size_t b)
30: {
31: return( (a32: }
33:
34: ssize_t my_write(int fd,void *buffer,size_t length)35: {
36: size_t bytes_left; //尚未写的文件大小37: size_t writesize = 4* 1024;
38: ssize_t written_bytes; //已经写的文件大小39: char *ptr;40: ptr=buffer;
41: bytes_left=length;
42: while(bytes_left>0)43: {
44: //开始写45: written_bytes=write(fd,ptr,min(bytes_left,writesize));
46: //出现了写错误47: if(written_bytes<=0)48: {
49: //中断错误,置零重新写50: if(errno==EINTR)51: written_bytes=0;
52: //其他错误,退出不写了53: else54: return(-1);55: }
56: //从剩下的地方继续写57: bytes_left-=written_bytes;
58: ptr+=written_bytes;
59: }
60: return(0);61: }
62:
63:
64:
65: int main(int argc, char *argv[])66: {
67: int sockfd; //通信套接字描述符68: char *buffer; //缓冲区69: struct sockaddr_in server_addr; //服务器地址结构70: struct hostent *host; //主机地址与名称信息结构71: int nbytes; //端口号、字节数72: FILE *fp; //文件指针73: int nfilesize; //文件大小74: char str[128]; //文件名75: char yes='Y'; //流程控制76: struct timeval tpstart,tpend; //用于记录文件传输时间77: float timeuse; //文件传输所用时间78: char *hostname="127.0.0.1";//主机名/ip地址79: int portnumber=4321;//端口号80:
81: //提示用户输入完整的命令行参数82: if(argc!=3)83: {
84: fprintf(stderr,"Usage:%s hostname portnumber\a\n",argv[0]);85: printf("using defaults:\nhostname: %s\nportnumber: %d\n",hostname,portnumber);86: }
87:
88: //如果利用用户输入的域名无法获得正确的主机地址信息,则退出89: if (argc>1)90: {
91: if((host=gethostbyname(argv[1]))==NULL)92: {
93: fprintf(stderr,"Gethostname error\n");94: exit(1);
95: }
96: }
97:
98: else99: if((host=gethostbyname(hostname))==NULL)100: {
101: fprintf(stderr,"Gethostname error\n");102: exit(1);
103: }
104:
105: if(argc>2)106:
107: //如果用户输入的端口不正确,则提示并退出108: if((portnumber=atoi(argv[2]))<0)109: {
110: fprintf(stderr,"Usage:%s hostname portnumber\a\n",argv[0]);111: exit(1);
112: }
113:
114: //客户程序开始建立 sockfd描述符,创建通信套接字115: if((sockfd=socket(AF_INET,SOCK_STREAM,6))==-1)116: {
117: fprintf(stderr,"Socket Error:%s\a\n",strerror(errno));118: exit(1);
119: }
120:
121:
122: //客户程序填充服务端的地址信息123: bzero(&server_addr,sizeof(server_addr));124: server_addr.sin_family=AF_INET;
125: server_addr.sin_port=htons(portnumber);
126: server_addr.sin_addr=*((struct in_addr *)host->h_addr);127:
128: //客户程序发起连接请求129: if(connect(sockfd,(struct sockaddr *)(&server_addr),sizeof(struct sockaddr))==-1)130: {
131: fprintf(stderr,"Connect Error:%s\a\n",strerror(errno));132: exit(1);
133: }
134: printf("Connection Succeed!\n");135:
136: while (toupper(yes)=='Y')137: {
138: //提示用户输入文件路径139: printf("Please input the file location:");140: scanf("%s",str);141: while ((fp=fopen(str,"r"))==NULL)142: {
143: fprintf(stderr,"File open error,Retry!\n");144: printf("Please input the file location:");145: scanf("%s",str);146: //exit(1);147: }
148: getchar();
149:
150: //获取打开的文件的大小,并将文件整个读入内存中151: fseek(fp,0L,SEEK_END);
152: nfilesize=ftell(fp);
153: rewind(fp);//most important!!!!!154: char *p=(char *)malloc(nfilesize);155: if (fread((void *)p,nfilesize,1,fp)<1) {156:
157: if (feof(fp))158: printf("read end of file!\nquit!\n");159: else160: printf("read file error!\n");161: }
162:
163: //将要传输的文件的大小信息发送给客户端164: if (my_write(sockfd,(void *)&nfilesize,4)==-1)165: {
166: fprintf(stderr,"Write Error:%s\n",strerror(errno));167: exit(1);
168: }
169:
170: printf("Begin to transfer the file!\n");171: getchar();
172:
173: //获取传输初始时间174: gettimeofday(&tpstart,NULL);
175:
176: //传输文件177: if (my_write(sockfd,p,nfilesize)==-1)178: {
179: fprintf(stderr,"Transfer failed!");180: exit(1);
181: }
182:
183: //获取传输结束时间184: gettimeofday(&tpend,NULL);
185: //计算整个传输用时186: timeuse=1000000*(tpend.tv_sec-tpstart.tv_sec)+(tpend.tv_usec-tpstart.tv_usec);
187: timeuse/=1000000;
188:
189: printf("Transfer Succeed!\nFile Name: %s\nFile Size: %d bytes\nTotal Time: %f seconds\nTransfer Speed: %f bytes/second",str,nfilesize,timeuse,((float)nfilesize)/timeuse);190: free(p); //释放文件内存191: fclose(fp); //关闭文件192: // printf("\nTransfer another file?(Y/N): ");193: //scanf("%c",&yes);194: // getchar();195: yes='n';196: }
197: //结束通讯,关闭套接字,关闭连接198: close(sockfd);
199: printf("\nClient Exit!~~\n");200: exit(0);
201: }
服务器端代码列表:
具体代码如下:
“tcpserver.h”
1: #ifndef TCPSERVER_H2: #define TCPSERVER_H3:
4: #include5:
6: //继承自QTcpServer,完成TCPSEVER的建立的类7:
8: class TcpServer : public QTcpServer9: {
10: Q_OBJECT
11: public:12: explicit TcpServer(QObject *parent = 0);13:
14: //此信号用来更新UI15: signals:
16: void bytesArrived(qint64,qint32,int);17:
18: //QTcpServer类自带的函数,详情参考Class Reference19: protected:20: void incomingConnection(int socketDescriptor);21:
22: };
23:
24: #endif // TCPSERVER_H
TCPSERVER继承QTcpServer,主要完成TCP服务器的建立,类中最主要的成员函数为虚函数incomingConnection(int socketDescriptor)的定义。
“tcpserver.cpp”
1: #include "tcpserver.h"2: #include "tcpthread.h"3:
4: //构造函数5:
6: TcpServer::TcpServer(QObject *parent) :
7: QTcpServer(parent)
8: {
9: }
10:
11: //重新定义了incomingConnection这个虚函数,12: //开辟一个新的tcpsocket线程,从TcpServer获得socketDescriptor,13: //并完成相应的信号连接。14:
15: void TcpServer::incomingConnection(int socketDescriptor)16: {
17:
18: TcpThread *thread = new TcpThread(socketDescriptor, this);19:
20: //将线程结束信号与线程的deleteLater槽关联21: connect(thread, SIGNAL(finished()),
22: thread, SLOT(deleteLater()));
23:
24: //关联相应的UI更新槽25: connect(thread,SIGNAL(bytesArrived(qint64,qint32,int)),26: this,SIGNAL(bytesArrived(qint64,qint32,int)));27:
28: //QT的线程都是从start开始,调用run()函数29: thread->start();
30: }
31:
极其简单的构造函数,在incomingConnection()中,定义一个线程TcpThread,并将socketDescriptor传递给其构造函数,完成线程的创建,并且调用QThread的start函数,开始执行线程的虚函数run()。
“tcpthread.h”
1: #ifndef TCPTHREAD_H2: #define TCPTHREAD_H3:
4: #include5: #include6: #include7:
8: //继承QThread的TCP传输线程9: //主要是完成run()虚函数的定义10: //还有一些辅助变量的声明11:
12: class QFile;13: class QTcpSocket;14:
15: class TcpThread : public QThread16: {
17: Q_OBJECT
18: public:19: TcpThread(int socketDescriptor, QObject *parent);20:
21: void run();22:
23: signals:
24: void error(QTcpSocket::SocketError socketError);25: void bytesArrived(qint64,qint32,int);26:
27: public slots:28: void receiveFile();29:
30: private:31: int socketDescriptor;32: qint64 bytesReceived; //收到的总字节33: qint64 byteToRead; //准备读取的字节34: qint32 TotalBytes; //总共传输的字节35: QTcpSocket *tcpSocket;
36: QHostAddress fileName; //文件名37: QFile *localFile;
38: QByteArray inBlock; //读取缓存39:
40:
41: };
42:
43: #endif // TCPTHREAD_H
继承自QThread类,在此线程中完成TCPSOCKET的建立,和文件的接收。
“tcpthread.cpp”
1: #include "tcpthread.h"2: #include3: #include4:
5: //构造函数完成简单的赋值/6: TcpThread::TcpThread(int socketDescriptor, QObject *parent):7: QThread(parent),socketDescriptor(socketDescriptor)
8: {
9: bytesReceived = 0;
10: }
11:
12: //因为QT的线程的执行都是从run()开始,13: //所以在此函数里完成tcpsocket的创建,相关信号的绑定14: void TcpThread::run()15: {
16: tcpSocket = new QTcpSocket;17:
18: //将Server传来的socketDescriptor与刚创建的tcpSocket关联19: if (!tcpSocket->setSocketDescriptor(socketDescriptor)) {20: emit error(tcpSocket->error());
21: return;22: }
23:
24: qDebug()<25:
26: //这是重中之重,必须加Qt::BlockingQueuedConnection!27: //这里困扰了我好几天,原因就在与开始没加,默认用的Qt::AutoConnection。28: //简单介绍一下QT信号与槽的连接方式:29: //Qt::AutoConnection表示系统自动选择相应的连接方式,如果信号与槽在同一线程,就采用Qt::DirectConnection,如果信号与槽不在同一线程,将采用Qt::QueuedConnection的连接方式。30: //Qt::DirectConnection表示一旦信号产生,立即执行槽函数。31: //Qt::QueuedConnection表示信号产生后,将发送Event给你的receiver所在的线程,postEvent(QEvent::MetaCall,...),slot函数会在receiver所在的线程的event loop中进行处理。32: //Qt::BlockingQueuedConnection表示信号产生后调用sendEvent(QEvent::MetaCall,...),在receiver所在的线程处理完成后才会返回;只能当sender,receiver不在同一线程时才可以。33: //Qt::UniqueConnection表示只有它不是一个重复连接,连接才会成功。如果之前已经有了一个链接(相同的信号连接到同一对象的同一个槽上),那么连接将会失败并将返回false。34: //Qt::AutoCompatConnection与QT3保持兼容性35: //说明一下,对于任何的QThread来说,其线程只存在于run()函数内,其它的函数都不在线程内,所以此处要采用Qt::BlockingQueuedConnection,36: //因为当SOCKET有数据到达时就会发出readyRead()信号,但是此时可能之前的receiveFile()还未执行完毕,之前使用的Qt::AutoConnection,37: //结果传输大文件的时候就会出错,原因就在于只要有数据到达的时候,就会连接信号,但是数据接收还没处理完毕,而Qt::BlockingQueuedConnection会阻塞38: //此连接,直到receiveFile()处理完毕并返回后才发送信号。39:
40: connect(tcpSocket, SIGNAL(readyRead()),
41: this, SLOT(receiveFile()),Qt::BlockingQueuedConnection);42:
43: exec();
44:
45:
46:
47:
48: }
49:
50: void TcpThread::receiveFile()51: {
52:
53:
54: //将tcpsocket封装到QDataStream里,便于使用操作符>>55: QDataStream in(tcpSocket);
56: if(bytesReceived < sizeof(qint32))57: {
58:
59: //先接收32bit的文件大小60: if(tcpSocket->bytesAvailable() >= sizeof(qint32))61: {
62:
63: in.setByteOrder(QDataStream::LittleEndian); //必须的,因为发送端为LINUX系统64:
65: in>>TotalBytes;
66:
67: TotalBytes += 4;
68: qDebug()<69:
70: bytesReceived += sizeof(qint32);71:
72: fileName = tcpSocket->peerAddress();
73: quint16 port = tcpSocket->peerPort();
74: localFile = new QFile(fileName.toString()+(tr(".%1").arg(port))); //用户端的IP地址作为保存文件名75: if (!localFile->open(QFile::WriteOnly ))76:
77: {
78:
85: }
86: }
87:
88: }
89:
90: //如果读取的文件小于文件大小就继续读91: if (bytesReceived < TotalBytes){92: byteToRead = tcpSocket->bytesAvailable();
93: bytesReceived += byteToRead;
94: inBlock = tcpSocket->readAll();
95:
96: qDebug()<<"bytesReceived is:"<97: localFile->write(inBlock);
98: inBlock.resize(0);
99: }
100:
101: emit bytesArrived(bytesReceived,TotalBytes,socketDescriptor);
102:
103: if (bytesReceived == TotalBytes) {104: localFile->close();
105: qDebug()<106: emit finished();
107: QApplication::restoreOverrideCursor();
108: }
109:
110: }
代码中已经有很详细的注释,需要再说明的一点就是在多线程的编写中,信号/槽的连接方式一定要根据实际情况来进行选择!
“widget.h”
1: #ifndef WIDGET_H2: #define WIDGET_H3:
4: #include5:
6: #include "tcpthread.h"7: #include "tcpserver.h"8:
9: class QDialogButtonBox;10:
11: class QTcpSocket;12: namespace Ui {13: class Widget;14: }
15:
16: class Widget : public QWidget17: {
18: Q_OBJECT
19:
20: public:21: explicit Widget(QWidget *parent = 0);22: ~Widget();
23:
24: private:25: Ui::Widget *ui;
26: TcpServer tcpServer;
27:
28:
29: private slots:30: void on_OkButton_clicked();31: void updateProgress(qint64,qint32,int);32:
33: };
34:
35: #endif // WIDGET_H
简单的widget类。
“widget.cpp”
1: #include "widget.h"2: #include "ui_widget.h"3: #include4: #include5:
6: Widget::Widget(QWidget *parent) :
7: QWidget(parent),
8: ui(new Ui::Widget)9: {
10: ui->setupUi(this);11: ui->progressBar->setMaximum(2);
12: ui->progressBar->setValue(0);
13: }
14:
15: Widget::~Widget()
16: {
17: delete ui;18: }
19:
20: void Widget::on_OkButton_clicked()21: {
22: ui->OkButton->setEnabled(false);
23:
24: QApplication::setOverrideCursor(Qt::WaitCursor);
25: //bytesReceived = 0;26:
27: while (!tcpServer.isListening() && !tcpServer.listen(QHostAddress::Any,12345))28: {
29: QMessageBox::StandardButton ret = QMessageBox::critical(this,30: tr("回环"),31: tr("无法开始测试: %1.")32: .arg(tcpServer.errorString()),
33: QMessageBox::Retry
34: | QMessageBox::Cancel);
35: if (ret == QMessageBox::Cancel)36: return;37: }
38: ui->statuslabel->setText(tr("监听端口:%1").arg("12345"));39: connect(&tcpServer,SIGNAL(bytesArrived(qint64,qint32,int)),40: this,SLOT(updateProgress(qint64,qint32,int)));41:
42:
43: }
44: void Widget::updateProgress(qint64 bytesReceived, qint32 TotalBytes, int socketDescriptor)45: {
46: ui->progressBar->setMaximum(TotalBytes);
47: ui->progressBar->setValue(bytesReceived);
48: ui->statuslabel->setText(tr("已接收 %1MB")49: .arg(bytesReceived / (1024 * 1024)));
50: ui->textBrowser->setText(tr("现在连接的socket描述符:%1").arg(socketDescriptor));51:
52:
53: }
完成服务器的监听,和进度条的更新。
点击开始后,处于监听状态。