使用http协议和winsockapi实现webzip文件下载
出处：论文网
时间：2007-04-13
mysocket:tsocket; myclient:tsockaddr;
recvbuf:array [0..332] of char; mycmdstr:string;
ptemp:pchar;
myhandle,index_ch,reccount,i:integer;
begin //创建本地socket
mysocket:=socket(af_inet,sock_stream,0);
if (mysocket=socket_error) then begin
application.messagebox(′初始化失败！′,′信息′,mb_ok);
exit;
end; //生成连接主机的结构
myclient.sin_family:=af_inet;
myclient.sin_port:=htons(connectedport);
// connectedport：全局变量，记录连接端口号
strpcopy(recvbuf,getserverip(fileurl));
// getserverip(fileurl)：返回服务器的ip
myclient.sin_addr.s_addr:=inet_addr(recvbuf); //连接服务器
if (connect(mysocket,myclient,sizeof(myclient))〈〉0) then begin
closesocket(mysocket);
exit;
end; //发请求
if (q_useproxy=0) then
mycmdstr:=′get ′＋extracturlpath(fileurl)＋′ http/1.1′
//extracturlpath(fileurl)返回相对url
else mycmdstr:=′get ′＋fileurl＋′ http/1.1′;//使用代理写全url
strpcopy(recvbuf,mycmdstr);
i:=length(mycmdstr);
recvbuf[i]:=＃13; inc(i); recvbuf[i]:=＃10; inc(i);
recvbuf[i]:=＃13; inc(i); recvbuf[i]:=＃10; inc(i);
recvbuf[i]:=＃0;
send(mysocket,recvbuf,i,0);
//发送请求读返回数据
reccount:=recv(mysocket,recvbuf,sizeof(recvbuf)－1,0); //判断是否成功
i:=0;
while i〈10 do begin
i:=i＋1;
// ′http/1.0 200 ok′是成功标志
if ((recvbuf[i]=′ ′) and (recvbuf[i＋1]=′2′) and (recvbuf[i＋2]=′0′)
and (recvbuf[i＋3]=′0′) and (recvbuf[i＋4]=′ ′)) then i:=200;
end;
if i〈〉200 then begin closesocket(mysocket); exit; end;
//得到数据起始位置
ptemp:=strpos(recvbuf,＃13＋＃10＋＃13＋＃10)＋4;
index_ch:=ptemp－recvbuf;
//建立下载目录
try forcedirectories(extractfilepath(getfillocalpath(fileurl)));
except
end; //创建文件
deletefile(getfillocalpath(fileurl));
myhandle:=filecreate(getfillocalpath(fileurl)); //如果未接收完则继续
while (reccount〈〉0) do
begin
filewrite(myhandle,recvbuf[index_ch] ,reccount－(index_ch));
index_ch:=0;
reccount:=recv(mysocket,recvbuf,sizeof(recvbuf)－1,0);
end; //关闭文件句柄和套接字
fileclose(myhandle);
closesocket(mysocket);
end;
