NDK开发中的一个HTTP下载实例附带下载进度

有一个控制下载的管理类吧，调用http下载类进行各种下载，同时在下载过程中可以显示其下载的进度，而且在每个下载结束之后以类似回调的方式告诉管理类，以继续进行后续的操作。

直接代码：

.h文件

 #pragma once
 #include <stdio.h>
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
 #include <netdb.h>
 #include <stdlib.h>
 #include <iostream>
 #include <string.h>
 #include <unistd.h>
 #include <fstream>
 #include <vector>
 #include <pthread.h>
 #include <android/log.h>
 using namespace std;

 class CHttpDownLoad
 {
 public:
     CHttpDownLoad(void);
     ~CHttpDownLoad(void);

 public:
     void    　　DownLoad(string str1,string str2,string str3,void* handler);
     int        GetDownState();
 private:
     int        GetFileSize(const char* host,const char* file,string* error,int& headersize);

 public:
     string        m_strIP;
     string        m_strFileName;
     string        m_strLocFile ;
     float        m_filesize ;
     int            m_hsize;
     int            m_iProgress;
     void        *m_pUdateBase;
 };

.cpp文件

 #include "stdafx.h"
 #include "CHttpDownLoad.h"
 #include <stdlib.h>
 #include "updateBase.h"

 typedef string::size_type (string::*find_t)(const string& delim,string::size_type offset) const;

 vector<string> Split(const string& s,const string& match,bool removeEmpty=false,bool fullMatch=false)
 {
     vector<string> result;
     string::size_type start = , skip = ;
     find_t pfind = &string::find_first_of;
     if (fullMatch)
     {
         skip = match.length();
         pfind = &string::find;
     }
     while (start != string::npos)
     {
         string::size_type end = (s.*pfind)(match, start);
         if (skip == ) end = string::npos;
         string token = s.substr(start, end - start);
         if (!(removeEmpty && token.empty()))
         {
             result.push_back(token);
         }
         if ((start = end) != string::npos) start += skip;
     }       

     return result;
 }

 void SplitProperty(vector<string> property,string* name,string *value)
 {
     vector<string>::iterator it=property.begin();
     if(it!= property.end())
     {
         name->clear();
         name->append(*it);
     }
     it++;
     if(it!= property.end())
     {
         value->clear();
         value->append(*it);
     }
 }

 CHttpDownLoad::CHttpDownLoad(void)
 {
     m_filesize = ;
     m_hsize = ;
     m_iProgress = ;
     m_pUdateBase = NULL;
 }

 CHttpDownLoad::~CHttpDownLoad(void)
 {
 }

 void DownloadFile(const char* host,
     const char* file,
     const char * savefile,
     float size,int hsize,
     int& progress,
     updateBase* handler
     )
 {
     struct sockaddr_in servaddr;
     struct hostent *hp;
     string info;
     int sock_id;
     //char message[18000] = {0};
     char *message = new char[];
     memset(message,,);
     //char messagetop[18000]={0};
     char *messagetop = new char[];
     memset(messagetop,,);
     int msglen;
     float readcount=;
     string request;
     request.append("GET ");
     request.append(file);
     request.append(" HTTP/1.1\n");
     request.append("Host:");
     request.append(host);
     request.append("\r\n\r\n");
     if((sock_id = socket(AF_INET, SOCK_STREAM, )) == -)
     {
         return;
     }
     memset(&servaddr,,sizeof(servaddr));
     if((hp = gethostbyname(host)) == NULL)
     {
         return;
     }
     memcpy((char *)&servaddr.sin_addr.s_addr, (char *)hp->h_addr, hp->h_length);
     servaddr.sin_port = htons();
     servaddr.sin_family = AF_INET;
     if(connect(sock_id, (struct sockaddr *)&servaddr, sizeof(servaddr)) != )
     {
         return;
     }
     write(sock_id,request.c_str(),request.length());
     ofstream outfile (savefile,ofstream::binary);
     do{
         msglen = read(sock_id,message,);
         if(msglen==)
         {
             break;
         }

         if(readcount==)
         {
             int tempindex=;
             //for(int i =hsize - 1;i<msglen;i++)
             for(int i =hsize;i<msglen;i++)
             {
                 messagetop[tempindex]= message[i];
                 tempindex=tempindex+;
             }
             outfile.write (messagetop,tempindex);
         }
         else
         {
             outfile.write (message,msglen);
         }
         readcount=readcount+msglen;
         progress = readcount/size*;
     }while(readcount<=(size+ hsize));
     outfile.close();
     close(sock_id);

     if (message != NULL)
     {
         delete[] message;
         message = NULL;
     }
     if (messagetop != NULL)
     {
         delete[] messagetop;
         messagetop = NULL;
     }

     handler->CallupdateBaseFinsh();//回调下载结束

 }

 void* UpdateWorCoping(void* data)
 {
     CHttpDownLoad *pGhttpFile = (CHttpDownLoad*)data;
     DownloadFile(pGhttpFile->m_strIP.c_str(),
         pGhttpFile->m_strFileName.c_str(),
         pGhttpFile->m_strLocFile.c_str(),
         pGhttpFile->m_filesize,
         pGhttpFile->m_hsize,
         pGhttpFile->m_iProgress,
         (updateBase*)pGhttpFile->m_pUdateBase
         );

     return ((void*));
 }

 int CHttpDownLoad::GetFileSize(const char* host,const char* file,string* error,int& headersize)
 {
     int size=-;
     struct sockaddr_in servaddr;
     struct hostent *hp;
     string splitline="\r\n";
     string PName;
     string PValue;
     string splittagbalue=":";
     string info;
     vector<string> properties;
     vector<string> property;
     int sock_id;
     //char message[1024*1024] = {0};
     char *message = new char[*];
     memset(message,,*);
     int msglen;
     string request;
     request.append("HEAD ");
     request.append(file);
     request.append(" HTTP/1.1\n");
     request.append("Host:");
     request.append(host);
     request.append("\r\n\r\n");
     if((sock_id = socket(AF_INET, SOCK_STREAM, )) == -)
     {
         error->append("Couldn't get a socket!");
         return size;
     }
     memset(&servaddr,,sizeof(servaddr)); 

     if((hp = gethostbyname(host)) == NULL)
     {
         error->append("Couldn't access network.");
         error->append(host);
         return size;
     }
     memcpy((char *)&servaddr.sin_addr.s_addr, (char *)hp->h_addr, hp->h_length);
     servaddr.sin_port = htons();
     servaddr.sin_family = AF_INET;
     if(connect(sock_id, (struct sockaddr *)&servaddr, sizeof(servaddr)) != )
     {
         error->append("Couldn't connect!");
         return size;
     }
     write(sock_id,request.c_str(),request.length());
     msglen = read(sock_id,message,*);
     headersize= msglen;
     info.append(message,,msglen);
     close(sock_id);
     properties =Split(info,splitline,true);
     vector<string>::iterator it;
     for (it=properties.begin(); it<properties.end(); it++)
     {
         property= Split(*it,splittagbalue,true);
         SplitProperty(property,&PName,&PValue);
         if(PName=="Content-Length")
         {
             size =atoi(PValue.c_str());
             break;
         }
     }
     if(size==-)
     {
         error->append("Resource Not Found!");
     }  

     if (message!=NULL)
     {
         delete[] message;
         message = NULL;
     }
     return size;

 }

 //给出的这样一个完整的url ："http://10.10.41.112/ressdir/test/111111111.lst"
 //对应下面几个参数为：（注意格式）
 //str1 = "10.10.41.112";
 //str2 = "//ressdir//test//111111111.lst";
 //str3 = "/mnt/sdcard/test/111111111.lst";

 void CHttpDownLoad::DownLoad(string str1,string str2,string str3,void *handler)
 {
     if (str1.empty()||str2.empty()||str3.empty()||handler == NULL)
     {
         LOGI("0___DownLoad is error!!!");
         return;
     }

     m_strIP = str1;
     m_strFileName= str2;
     m_strLocFile = str3;
     m_pUdateBase = handler;

     string error;
     m_filesize = GetFileSize(str1.c_str(),str2.c_str(),&error,m_hsize);
     if (m_filesize<=)
     {
         LOGI("1_____DownLoad is error!!!");
         return;
     }

     pthread_t thread_id;
     pthread_attr_t attr;
     pthread_attr_init(&attr);
     pthread_attr_setdetachstate(&attr,PTHREAD_CREATE_DETACHED);
     pthread_create(&thread_id,&attr,UpdateWorCoping,this);

     m_thread_id = thread_id;
     pthread_attr_destroy(&attr);
 }

 int    CHttpDownLoad::GetDownState()
 {
     return m_iProgress;//用于下载进度
 }

其中 updateBase 就是那个下载管理类，这里就不在贴出了。

在管理类中调用 DownLoad(string str1,string str2,string str3,void *handler);//此处主要格式，handler参数为下载管理类指针用于下载结束的回调

理进行http下载。

在下载过程中调用 GetDownStae() 获取下载的进度以用于其它目的。