基于UDP的文件传输实验报告

实验报告成 绩2015年6月 8 日 课程名称 《数据库技术》 学生姓名 *** 学 号 ******** 专业班级 电子信息工程 指导教师实验名称：基于UDP的文件传输1．实验目的（1）熟练掌握Socket编程；（2）分析UDP与TCP的异同。

2．实验设备和条件硬件环境：PC机操作系统：Windows 或者Linux语言环境：Visual C++ ，VS，GCC，Java均可3．实验要求参考TCP文件传输demo, 基于UDP实现send.mp3文件的传输，并测试接收到的文件与发送的文件是否一致。

请各位同学于第15周星期三或星期四上课时将纸质版（双面打印）上交！4．实验内容：测试数据与实验结果（可以抓图粘贴）（1）发送端代码。

#include"stdafx.h"#include<Winsock2.h>#include<stdio.h>#define MAX_LENGTH 1024int_tmain(int argc, _TCHAR* argv[]){WORD wVersionRequested;WSADATA wsaData;wVersionRequested = MAKEWORD(2, 2);if (WSAStartup(wVersionRequested, &wsaData) != 0)//初始化ws2_32.dll动态库{printf("WSAStartup() failed!\n");//Winsock初始化错误exit(-1);}if (wsaData.wVersion != wVersionRequested){printf("The version of Winsock is not suited!\n");//Winsock版本不匹配WSACleanup();//结束对ws2_32.dll的调用exit(-2);}//说明ws2_32.dll正确加载printf("Load ws2_32.dll successfully!\n");//创建套接字SOCKET servsock;printf("Create Socket...\n");servsock = socket(AF_INET, SOCK_DGRAM, 0);//数据报套接字int servport = 5555;int iSockErr = 0;//定义服务器地址结构sockaddr_in udpaddr;int len = sizeof(udpaddr);memset(&udpaddr, 0, sizeof(udpaddr));udpaddr.sin_family = AF_INET;udpaddr.sin_port = htons(servport);//将一个点分十进制IP地址字符串转换成32位数字表示的IP地址udpaddr.sin_addr.s_addr = inet_addr("172.16.4.94");////INADDR_ANY//读取mp3文件FILE *fp = NULL;errno_t err;err = fopen_s(&fp, "七里香.mp3", "rb");if (fp == NULL){printf("Open File Failed!\n");getchar();exit(-5);}char buffer[MAX_LENGTH] = "\0";char *bufptr = buffer;int i = 0;while (!feof(fp)){int iBytesRead = fread(bufptr, 1, MAX_LENGTH, fp);int iRet = sendto(servsock, buffer, sizeof(buffer), 0, (struct sockaddr*)&udpaddr, len);if (iRet != SOCKET_ERROR){iRet = recvfrom(servsock, buffer, sizeof(buffer), 0, (struct sockaddr*)&udpaddr, &len);}else{printf("send file failed!\n");break;}if (iRet == SOCKET_ERROR){//closesocket(clisock);printf("send file failed!\n");break;}else if (iRet == 0){printf("send mp3 file successfully!\n");break;}if (iBytesRead == 0){printf("send mp3 file successfully!\n");break;}//printf("%d", &len);printf("send packet %d lenth: %d\n", i++, iBytesRead);Sleep(10);}sendto(servsock, "", 0, 0, (struct sockaddr*)&udpaddr, len);//关闭shutdown(servsock, 2);closesocket(servsock);WSACleanup();getchar();return 0;}（2）接收端代码。

#include"stdafx.h"#include<Winsock2.h>#include<stdio.h>#define MAX_LENGTH 1024*10int _tmain(int argc, _TCHAR* argv[]){WORD wVersionRequested;WSADATA wsaData;wVersionRequested = MAKEWORD(2, 2);if (WSAStartup(wVersionRequested, &wsaData) != 0)//初始化ws2_32.dll动态库{printf("WSAStartup() failed!\n");//Winsock初始化错误exit(-1);}if (wsaData.wVersion != wVersionRequested){printf("The version of Winsock is not suited!\n");//Winsock版本不匹配WSACleanup();//结束对ws2_32.dll的调用exit(-2);}//说明ws2_32.dll正确加载printf("Load ws2_32.dll successfully!\n");//获取本机IP地址char PCname[100] = { "" };char *IPaddress = NULL;gethostname(PCname, sizeof(PCname));printf("Local Hostname is %s.\n", PCname);struct hostent FAR * lpHostEnt = gethostbyname(PCname);if (lpHostEnt == NULL){//产生错误printf("gethostbyname failed!\n");return -1;}//获取IPLPSTR lpAddr = lpHostEnt->h_addr_list[0];if (lpAddr){struct in_addr inAddr;memmove(&inAddr, lpAddr, 4);//转换为标准格式IPaddress = inet_ntoa(inAddr);//将一个32位数字表示的IP地址转换成点分十进制IP地址字符串if (sizeof(IPaddress) == 0)printf("get host IP failed!\n");elseprintf("Local HostIP is %s.\n", IPaddress);}//创建套接字//SOCKET servsock, clisock;SOCKET servsock;printf("Create Socket...\n");servsock = socket(AF_INET, SOCK_DGRAM, 0);//数据报套接字int servport = 5555;int iSockErr = 0;//定义服务器地址结构sockaddr_in udpaddr, cliaddr;memset(&udpaddr, 0, sizeof(udpaddr));memset(&cliaddr, 0, sizeof(cliaddr));int clilen = sizeof(cliaddr);udpaddr.sin_family = AF_INET;udpaddr.sin_port = htons(servport);//将一个点分十进制IP地址字符串转换成32位数字表示的IP地址udpaddr.sin_addr.s_addr = inet_addr(IPaddress);//"127.0.0.1"//INADDR_ANY//绑定套接字到服务器地址结构printf("Binding...\n");iSockErr = bind(servsock, (sockaddr *)&udpaddr, sizeof(udpaddr));if (iSockErr == SOCKET_ERROR){printf("Binding failed:%d\n", WSAGetLastError());//根据不同的错误类型进行不同的处理exit(-3);}//函数调用成功，进行其他处理char buff[256] = "\0";char buffer[MAX_LENGTH] = "\0";int len = 0;//接收欢迎词memset(buffer, 0, sizeof(buffer));FILE *fp = NULL;errno_t err;err = fopen_s(&fp, "七里香.mp3", "wb");int i = 0;while (1){len = recvfrom(servsock, buffer, sizeof(buffer), 0, (struct sockaddr*)&cliaddr, &clilen);if (len == SOCKET_ERROR) {printf("recv error!\n");break;}else if (len == 0){printf("recv finished!\n");break;}buffer[len] = 0;printf("received packet %d lenth: %d\n\n", i++, len);fwrite(buffer, 1, len, fp);sendto(servsock, buff, sizeof(buff), 0, (struct sockaddr*)&cliaddr, clilen);Sleep(8);//printf("%d\n",&len);}fclose(fp);//shutdown(clisock, 2);// closesocket(clisock);shutdown(servsock, 2);closesocket(servsock);WSACleanup();getchar();return 0;}（3）简单的代码移植后接收端是否能正确接收？如果不能请分析原因，并尝试调整发送端读取数据的大小和延迟时间，以及接收端缓冲区的大小来解决数据丢包问题。