linux下HttpGet、HttpPost的C++实现

#include "HttpRequest.h"

int main()
{
	HttpRequest* Http = new HttpRequest;
	
	char* str = (char*)malloc(BUFSIZE);
	
	memset(str, 0, BUFSIZE);
	if(Http->HttpGet("http://www.baidu.com", str)) {
		printf("%s\n", str);
	} else {
		printf("http://www.baidu.com HttpGet请求失败!\n");
	}
	
	memset(str, 0, BUFSIZE);	
	//安装Tomcat
	if(Http->HttpGet("127.0.0.1", str)) {
		printf("%s\n", str);
	} else {
		printf("127.0.0.1 HttpGet请求失败!\n");
	}

	free(str);
	return 0;
}

#ifndef __HTTP__
#define __HTTP__

#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <netdb.h>
#include <stdarg.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/types.h>      
#include <sys/socket.h>

#define BUFSIZE 41000
#define URLSIZE 1024
#define INVALID_SOCKET -1
#define __DEBUG__

class HttpRequest
{
	public:
		HttpRequest();
		~HttpRequest();
		void DebugOut(const char *fmt, ...);
		
		int HttpGet(const char* strUrl, char* strResponse);
		int HttpPost(const char* strUrl, const char* strData, char* strResponse);

	private:
		int   HttpRequestExec(const char* strMethod, const char* strUrl, const char* strData, char* strResponse);
		char* HttpHeadCreate(const char* strMethod, const char* strUrl, const char* strData);
		char* HttpDataTransmit(char *strHttpHead, const int iSockFd);
			
		int   GetPortFromUrl(const char* strUrl);
		char* GetIPFromUrl(const char* strUrl);
		char* GetParamFromUrl(const char* strUrl);
		char* GetHostAddrFromUrl(const char* strUrl);
		
		int   SocketFdCheck(const int iSockFd);	
		
		static int m_iSocketFd;
};

#endif

#include "HttpRequest.h"

HttpRequest::HttpRequest()
{
	
}

HttpRequest::~HttpRequest()
{
	
}


/**
*	功能描述：HttpGet请求
*	参数说明：
*				strUrl：     Http请求URL
*				strResponse：Http请求响应
*	返 回 值：
*				1表示成功
*				0表示失败
**/
int HttpRequest::HttpGet(const char* strUrl, char* strResponse)
{
	return HttpRequestExec("GET", strUrl, NULL, strResponse);
}


/**
*	功能描述：HttpPost请求
*	参数说明：
*				strUrl：     Http请求URL
*               strData：    POST请求发送的数据
*				strResponse：Http请求响应
*	返 回 值：
*				1表示成功
*				0表示失败
**/
int HttpRequest::HttpPost(const char* strUrl, const char* strData, char* strResponse)
{
	return HttpRequestExec("POST", strUrl, strData, strResponse);
}


//执行HTTP请求，GET或POST
int HttpRequest::HttpRequestExec(const char* strMethod, const char* strUrl, const char* strData, char* strResponse)
{
	//判断URL是否有效
	if((strUrl == NULL) || (0 == strcmp(strUrl, ""))) {
		DebugOut("%s %s %d\tURL为空\n", __FILE__, __FUNCTION__, __LINE__); 
		return 0;
	}
	
	//限制URL长度
	if(URLSIZE < strlen(strUrl)) {
		DebugOut("%s %s %d\tURL的长度不能超过%d\n", __FILE__, __FUNCTION__, __LINE__, URLSIZE); 
		return 0;
	}
	
	//创建HTTP协议头
	char* strHttpHead = HttpHeadCreate(strMethod, strUrl, strData);
	
	//判断套接字m_iSocketFd是否有效，有效就直接发送数据
	if(m_iSocketFd != INVALID_SOCKET) {
		//检查SocketFd是否为可写不可读状态
		if(SocketFdCheck(m_iSocketFd) > 0) {
			char* strResult = HttpDataTransmit(strHttpHead, m_iSocketFd);
			if(NULL != strResult) {
				strcpy(strResponse, strResult);
				return 1;
			}
		}
	}

	//Create socket
	m_iSocketFd = INVALID_SOCKET;
	m_iSocketFd = socket(AF_INET, SOCK_STREAM, 0); 
    if (m_iSocketFd < 0 ) { 
		DebugOut("%s %s %d\tsocket error! Error code: %d，Error message: %s\n", __FILE__, __FUNCTION__, __LINE__, errno, strerror(errno)); 
		return 0;
	}
  
	//Bind address and port
	int iPort = GetPortFromUrl(strUrl);
	if(iPort < 0) {
		DebugOut("%s %s %d\t从URL获取端口失败\n", __FILE__, __FUNCTION__, __LINE__); 
		return 0;
	}	
	char* strIP = GetIPFromUrl(strUrl);
	if(strIP == NULL) {
		DebugOut("%s %s %d\t从URL获取IP地址失败\n", __FILE__, __FUNCTION__, __LINE__);
		return 0;
	}
	struct sockaddr_in servaddr;
	bzero(&servaddr, sizeof(servaddr)); 
	servaddr.sin_family = AF_INET; 
	servaddr.sin_port = htons(iPort); 
	if (inet_pton(AF_INET, strIP, &servaddr.sin_addr) <= 0 ) { 
	  DebugOut("%s %s %d\tinet_pton error! Error code: %d，Error message: %s\n", __FILE__, __FUNCTION__, __LINE__, errno, strerror(errno)); 
	  close(m_iSocketFd);
	  m_iSocketFd = INVALID_SOCKET;
	  return 0; 
	}
	
	//Set non-blocking
	int flags = fcntl(m_iSocketFd, F_GETFL, 0);
	if(fcntl(m_iSocketFd, F_SETFL, flags|O_NONBLOCK) == -1) {
		close(m_iSocketFd);
		m_iSocketFd = INVALID_SOCKET;
		DebugOut("%s %s %d\tfcntl error! Error code: %d，Error message: %s\n", __FILE__, __FUNCTION__, __LINE__, errno, strerror(errno)); 
		return 0;
	}

	//非阻塞方式连接
	int iRet = connect(m_iSocketFd, (struct sockaddr *)&servaddr, sizeof(servaddr));
	if(iRet == 0) {
		char* strResult = HttpDataTransmit(strHttpHead, m_iSocketFd);
		if(NULL != strResult) {
			strcpy(strResponse, strResult);
			free(strResult);
			return 1;
		} else {
			close(m_iSocketFd);
		    m_iSocketFd = INVALID_SOCKET;
			free(strResult);
			return 0;
		}
	}
	else if(iRet < 0) {
		if(errno != EINPROGRESS) {
			return 0;
		}
	}
	
	iRet = SocketFdCheck(m_iSocketFd);
	if(iRet > 0) {
		char* strResult = HttpDataTransmit(strHttpHead, m_iSocketFd);
		if(NULL == strResult) {
			close(m_iSocketFd);
		    m_iSocketFd = INVALID_SOCKET;
			return 0;
		}
		else {
			strcpy(strResponse, strResult);
			free(strResult);
			return 1;
		}
	}
	else {
		close(m_iSocketFd);
		m_iSocketFd = INVALID_SOCKET;
		return 0;
	}
	
	return 1;
}


//构建HTTP消息头
char* HttpRequest::HttpHeadCreate(const char* strMethod, const char* strUrl, const char* strData)
{
	char* strHost = GetHostAddrFromUrl(strUrl);
	char* strParam = GetParamFromUrl(strUrl);
	
	char* strHttpHead = (char*)malloc(BUFSIZE);
	memset(strHttpHead, 0, BUFSIZE);

	strcat(strHttpHead, strMethod); 
	strcat(strHttpHead, " /"); 
	strcat(strHttpHead, strParam);
	free(strParam);
	strcat(strHttpHead, " HTTP/1.1\r\n");
	strcat(strHttpHead, "Accept: */*\r\n");   
	strcat(strHttpHead, "Accept-Language: cn\r\n"); 
	strcat(strHttpHead, "User-Agent: Mozilla/4.0\r\n");
	strcat(strHttpHead, "Host: "); 
	strcat(strHttpHead, strHost);
	strcat(strHttpHead, "\r\n");
	strcat(strHttpHead, "Cache-Control: no-cache\r\n"); 
	strcat(strHttpHead, "Connection: Keep-Alive\r\n");
	if(0 == strcmp(strMethod, "POST"))
	{
		char len[8] = {0};
		unsigned uLen = strlen(strData);
		sprintf(len, "%d", uLen);		
		
		strcat(strHttpHead, "Content-Type: application/x-www-form-urlencoded\r\n");
		strcat(strHttpHead, "Content-Length: "); 
        strcat(strHttpHead, len); 
        strcat(strHttpHead, "\r\n\r\n"); 
        strcat(strHttpHead, strData); 
	}
	strcat(strHttpHead, "\r\n\r\n");
	
	free(strHost);
	
	return strHttpHead;	
}


//发送HTTP请求并接受响应
char* HttpRequest::HttpDataTransmit(char *strHttpHead, const int iSockFd)
{
	char* buf = (char*)malloc(BUFSIZE);
	memset(buf, 0, BUFSIZE);
	int ret = send(iSockFd,(void *)strHttpHead,strlen(strHttpHead)+1,0); 
	free(strHttpHead);
	if (ret < 0) { 
		DebugOut("%s %s %d\tsend error! Error code: %d，Error message: %s\n", __FILE__, __FUNCTION__, __LINE__, errno, strerror(errno)); 
		close(iSockFd);
		return NULL; 
	}
	
	while(1)
	{
		ret = recv(iSockFd, (void *)buf, BUFSIZE,0); 
		if (ret == 0) //连接关闭
		{  		
			close(iSockFd);
			return NULL; 
		}
		else if(ret > 0) {						
			return buf; 
		}
		else if(ret < 0) //出错
		{ 
			if(errno == EINTR || errno == EWOULDBLOCK || errno == EAGAIN) {
				continue;
			}
			else {
				close(iSockFd);
				return NULL;
			}
		}
	}
}


//从HTTP请求URL中获取主机地址，网址或者点分十进制IP地址
char* HttpRequest::GetHostAddrFromUrl(const char* strUrl)
{	
	char url[URLSIZE] = {0};
	strcpy(url, strUrl);
	
	char* strAddr = strstr(url, "http://");//判断有没有http://
	if(strAddr == NULL) {
		strAddr = strstr(url, "https://");//判断有没有https://
		if(strAddr != NULL) {
			strAddr += 8;
		}
	} else {
		strAddr += 7;
	}
	
	if(strAddr == NULL) {
		strAddr = url;
	}
	int iLen = strlen(strAddr);
	char* strHostAddr = (char*)malloc(iLen+1);
	memset(strHostAddr, 0, iLen+1);
	for(int i=0; i<iLen+1; i++) {
		if(strAddr[i] == '/') {
			break;
		} else {
			strHostAddr[i] = strAddr[i];
		}
	}

	return strHostAddr;
}


//从HTTP请求URL中获取HTTP请参数
char* HttpRequest::GetParamFromUrl(const char* strUrl)
{	
	char url[URLSIZE] = {0};
	strcpy(url, strUrl);
	
	char* strAddr = strstr(url, "http://");//判断有没有http://
	if(strAddr == NULL) {
		strAddr = strstr(url, "https://");//判断有没有https://
		if(strAddr != NULL) {
			strAddr += 8;
		}
	} else {
		strAddr += 7;
	}
	
	if(strAddr == NULL) {
		strAddr = url;
	}
	int iLen = strlen(strAddr);
	char* strParam = (char*)malloc(iLen+1);
	memset(strParam, 0, iLen+1);
	int iPos = -1;
	for(int i=0; i<iLen+1; i++) {
		if(strAddr[i] == '/') {
			iPos = i;
			break;
		}
	}
	if(iPos == -1) {
		strcpy(strParam, "");;
	} else {
		strcpy(strParam, strAddr+iPos+1);
	}
	return strParam;
}


//从HTTP请求URL中获取端口号
int HttpRequest::GetPortFromUrl(const char* strUrl)
{
	int iPort = -1;
	char* strHostAddr = GetHostAddrFromUrl(strUrl);	
	if(strHostAddr == NULL) {
		return -1;
	}
	
	char strAddr[URLSIZE] = {0};
	strcpy(strAddr, strHostAddr);
	free(strHostAddr);
	
	char* strPort = strchr(strAddr, ':');
	if(strPort == NULL) {
		iPort = 80;
	} else {
		iPort = atoi(++strPort);
	}
	return iPort;
}


//从HTTP请求URL中获取IP地址
char* HttpRequest::GetIPFromUrl(const char* strUrl)
{
	char* strHostAddr = GetHostAddrFromUrl(strUrl);
	int iLen = strlen(strHostAddr);
	char* strAddr = (char*)malloc(iLen+1);
	memset(strAddr, 0, iLen+1);
	int iCount = 0;
	int iFlag = 0;
	for(int i=0; i<iLen+1; i++) {
		if(strHostAddr[i] == ':') {
			break;
		}
		
		strAddr[i] = strHostAddr[i];
		if(strHostAddr[i] == '.') {
			iCount++;
			continue;
		}
		if(iFlag == 1) {
			continue;
		}
		
		if((strHostAddr[i] >= '0') || (strHostAddr[i] <= '9')) {
			iFlag = 0;
		} else {
			iFlag = 1;
		}
	}
	free(strHostAddr);
	
	if(strlen(strAddr) <= 1) {
		return NULL;
	}
	
	//判断是否为点分十进制IP地址，否则通过域名地址获取IP地址
	if((iCount == 3) && (iFlag == 0)) {
		return strAddr;
	} else {
		struct hostent *he = gethostbyname(strAddr);
		free(strAddr);
		if (he == NULL) {
			return NULL;
		} else {
			struct in_addr** addr_list = (struct in_addr **)he->h_addr_list;			 
			for(int i = 0; addr_list[i] != NULL; i++) {
				return inet_ntoa(*addr_list[i]);
			}
			return NULL;
		}
	}
}


//检查SocketFd是否为可写不可读状态
int HttpRequest::SocketFdCheck(const int iSockFd)
{
	struct timeval timeout ;
	fd_set rset,wset;
	FD_ZERO(&rset);
	FD_ZERO(&wset);
	FD_SET(iSockFd, &rset);
    FD_SET(iSockFd, &wset);
    timeout.tv_sec = 3;
	timeout.tv_usec = 500;
	int iRet = select(iSockFd+1, &rset, &wset, NULL, &timeout);
	if(iRet > 0)
	{
		//判断SocketFd是否为可写不可读状态
		int iW = FD_ISSET(iSockFd,&wset);
		int iR = FD_ISSET(iSockFd,&rset);
		if(iW && !iR)
		{
			char error[4] = "";
			socklen_t len = sizeof(error);
			int ret = getsockopt(iSockFd,SOL_SOCKET,SO_ERROR,error,&len);
			if(ret == 0)
			{
				if(!strcmp(error, ""))
				{
					return iRet;//表示已经准备好的描述符数
				}
				else 
				{
					DebugOut("%s %s %d\tgetsockopt error code:%d,error message:%s", __FILE__, __FUNCTION__, __LINE__, errno, strerror(errno));
				}
			}
			else
			{
				DebugOut("%s %s %d\tgetsockopt failed. error code:%d,error message:%s", __FILE__, __FUNCTION__, __LINE__, errno, strerror(errno));
			}
		}
		else
		{			
			DebugOut("%s %s %d\tsockFd是否在可写字符集中：%d，是否在可读字符集中：%d\t(0表示不在)\n", __FILE__, __FUNCTION__, __LINE__, iW, iR);
		}
	}
	else if(iRet == 0)
	{
		return 0;//表示超时
	}
	else
	{
		return -1;//select出错，所有描述符集清0
	}
	return -2;//其他错误
}


//打印输出
void HttpRequest::DebugOut(const char *fmt, ...)
{
#ifdef __DEBUG__
	va_list ap;
	va_start(ap, fmt);
	vprintf(fmt, ap);
	va_end(ap);
#endif
}


int HttpRequest::m_iSocketFd = INVALID_SOCKET;

代码下载地址：http://download.csdn.net/detail/dezhihuang/9515232

参考文档：http://blog.chinaunix.net/uid-27766566-id-3463221.html