【网络编程】UDP数据传输及文件传输实验

实验要求：

内容1：利用数据报套接字实现数据传输

1.    客户端创建UDP套接字，向指定的服务端发送数据；

2.    服务端接收到新数据，显示是谁发送过来的，并把该数据回传给发送方；

3.    服务端使用多线程来实现并发。

4.    观察在服务端启动和不启动时，客户端的运行情况。

内容2：使用UDP套接字实现文件传输

1.    客户端向服务端发送文件名

2.    客户端向服务端传输文件内容；

3.    双方关闭套接字。

4.    注意收发速度对文件传输结果的影响。

源码

客户端

#include "stdafx.h" #include <iostream>#include <stdio.h>  #include <winsock2.h>  #include <windows.h>using namespace std;#pragma comment(lib, "ws2_32.lib")   const int MAX_IP_PATH = 15;const int  MAX_BUFFER = 10240;const int NAME = 10240;int main(int argc, char* argv[]){WORD socketVersion = MAKEWORD(2, 2);WSADATA wsaData;if (WSAStartup(socketVersion, &wsaData) != 0){return 0;}SOCKET ClientSocket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);if (ClientSocket == INVALID_SOCKET){cout << "Create Socket Failed::" << GetLastError() << endl;WSACleanup();return -1;}char IP_ADDRESS[MAX_IP_PATH];unsigned int PORT;cout << "connect IP:";cin >> IP_ADDRESS;cout << endl;cout << "connect port:";cin >> PORT;cout << endl;sockaddr_in sin;sin.sin_family = AF_INET;sin.sin_port = htons(PORT);sin.sin_addr.S_un.S_addr = inet_addr(IP_ADDRESS);//消息发送回传unsigned int msglen;char SendBuffer[MAX_BUFFER];int len = sizeof(sin);cout << "input message:";cin >> SendBuffer;cout << endl;msglen = strlen(SendBuffer);sendto(ClientSocket, SendBuffer, strlen(SendBuffer), 0, (sockaddr *)&sin, len);int Ret;char RecvBuffer[MAX_BUFFER];Ret = recvfrom(ClientSocket, RecvBuffer, msglen, 0, (sockaddr *)&sin, &len);if (Ret <0){cout << "receive error:" << WSAGetLastError();closesocket(ClientSocket);WSACleanup();return -1;}RecvBuffer[Ret] = 0;cout << "receive message: " << RecvBuffer << endl;unsigned int ThreadPORT;Ret = recvfrom(ClientSocket, (char *)&ThreadPORT, msglen, 0, (sockaddr *)&sin, &len);if (Ret <0){cout << "receive post error " << WSAGetLastError();system("pause");return -1;}cout << "receive post:" <<ThreadPORT << endl;sin.sin_port = htons(ThreadPORT);//文件传输char filename[NAME];cout << "file name:\n";cin >> filename;sendto(ClientSocket, filename, strlen(filename), 0, (sockaddr *)&sin, len);FILE *fp = fopen(filename, "rb");if (fp == NULL){printf("create file failed\n");system("pause");return -1;}fseek(fp, 0L, SEEK_END);unsigned int size = ftell(fp);  cout << "file size:" << size << endl;fseek(fp, 0, SEEK_SET);sendto(ClientSocket, (char *)&size, 4, 0, (sockaddr *)&sin, len);int cnt = 1;unsigned int Length;cout << "begin to send file...." << endl;while (size > 0){memset(SendBuffer, 0, sizeof(char));if (size >= MAX_BUFFER){Length = fread(SendBuffer, sizeof(char), MAX_BUFFER, fp);size-= MAX_BUFFER;}else{Length = fread(SendBuffer, sizeof(char), Length, fp);size=0;}sendto(ClientSocket, SendBuffer, (int)Length, 0, (sockaddr *)&sin, len);cout << "pack " << cnt++ << ", file " << size << endl;}closesocket(ClientSocket);cout << "send file ok" << endl;;system("pause");WSACleanup();return 0;}

服务端

#include "stdafx.h" #include <iostream>#include <cstdio>  #include <winsock2.h> #include <windows.h>using namespace std;#pragma comment(lib, "ws2_32.lib")   const unsigned int POST = 8000;const int MAX_BUFFER = 10240;const int NAME = 10240;DWORD WINAPI ClientThread(LPVOID lpParameter){SOCKET ClientSocket = (SOCKET)lpParameter;sockaddr_in remoteAddr;int nAddrLen = sizeof(remoteAddr);int Ret = 0;char name[NAME];Ret = recvfrom(ClientSocket, name, MAX_BUFFER, 0, (sockaddr *)&remoteAddr, &nAddrLen);if (Ret <= 0){cout << "Receive Error£¡" << WSAGetLastError();return -1;}name[Ret] = 0;printf("Receive FileName From Client :: %s\n", name);unsigned int length;recvfrom(ClientSocket, (char*)&length, 4, 0, (sockaddr *)&remoteAddr, &nAddrLen);cout << "flie length :" << length << endl;FILE *fp = NULL;fp = fopen(name, "ab");if (fp == NULL){printf("Open File Error£¡\n");return -1;}cout << "begin to get file...." << endl;int cnt = 0;char RecvBuffer[MAX_BUFFER];while (length>0){memset(RecvBuffer, 0, sizeof(RecvBuffer));Ret = recvfrom(ClientSocket, RecvBuffer, MAX_BUFFER, 0, (sockaddr *)&remoteAddr, &nAddrLen);if (Ret <= 0){cout << "receive error " << WSAGetLastError() << endl;;closesocket(ClientSocket);fclose(fp);return -1;}fwrite(RecvBuffer, sizeof(char), Ret, fp);fflush(fp);length -= Ret;cout << "pack " << ++cnt << "file " << length << endl;}cout << "get file" << endl;closesocket(ClientSocket);fclose(fp);}int main(int argc, char* argv[]){WORD sockVersion = MAKEWORD(2, 2);WSADATA wsaData;if (WSAStartup(sockVersion, &wsaData) != 0){return 0;}SOCKET serSocket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);if (serSocket == INVALID_SOCKET){printf("socket error !");WSACleanup();return 0;}sockaddr_in serAddr;serAddr.sin_family = AF_INET;serAddr.sin_port = htons(POST);serAddr.sin_addr.S_un.S_addr = INADDR_ANY;if (bind(serSocket, (sockaddr *)&serAddr, sizeof(serAddr)) == SOCKET_ERROR){printf("bind error !");closesocket(serSocket);WSACleanup();return 0;}cout << "listening the client" << endl;sockaddr_in remoteAddr;int nAddrLen = sizeof(remoteAddr);int cnt = 0;char RecvBuffer[MAX_BUFFER];while (true){memset(RecvBuffer, 0, sizeof(RecvBuffer));int Ret = recvfrom(serSocket, RecvBuffer, MAX_BUFFER, 0, (sockaddr *)&remoteAddr, &nAddrLen);if (Ret < 0){cout << "receive error " << WSAGetLastError();continue;}RecvBuffer[Ret] = 0x00;cout << "client " << ++cnt << ": " << inet_ntoa(remoteAddr.sin_addr) << endl;printf("say:%s\n", RecvBuffer);sendto(serSocket, RecvBuffer, strlen(RecvBuffer), 0, (sockaddr *)&remoteAddr, nAddrLen);SOCKET ClientSocket;ClientSocket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);if (ClientSocket == INVALID_SOCKET){printf("socket error !");WSACleanup();continue;}sockaddr_in ClientAddr;unsigned int ThreadPORT = POST;while (ThreadPORT <= 65535){++ThreadPORT;ClientAddr.sin_family = AF_INET;ClientAddr.sin_port = htons(ThreadPORT);ClientAddr.sin_addr.S_un.S_addr = INADDR_ANY;if (bind(ClientSocket, (sockaddr *)&ClientAddr, sizeof(ClientAddr)) != SOCKET_ERROR)break;}if (ThreadPORT > 65535){cout << "creat thread failed" << endl;continue;}cout << "the post " << ThreadPORT << " to client  " << cnt << endl;sendto(serSocket, (const char*)&ThreadPORT, sizeof(unsigned int), 0, (sockaddr *)&remoteAddr, nAddrLen);HANDLE hThread = CreateThread(NULL, 0, ClientThread, (LPVOID)ClientSocket, 0, NULL);if (hThread == NULL){cout << "Create Thread Failed!" << endl;continue;}CloseHandle(hThread);}closesocket(serSocket);WSACleanup();return 0;}