PHP实现的下载远程文件类定义与用法示例

　　本文实例讲述了PHP实现的下载远程文件类定义与用法。分享给大家供大家参考，具体如下：

　　 <?php /** * 下载远程文件类支持断点续传 */ class HttpDownload { private $m_url = ; private $m_urlpath = ; private $m_scheme = http; private $m_host = ; private $m_port = 80; private $m_user = ; private $m_pass = ; private $m_path = /; private $m_query = ; private $m_fp = ; private $m_error = ; private $m_httphead = ; private $m_html = ; /** * 初始化 */ public function PrivateInit($url){ $urls = ; $urls = @parse_url($url); $this->m_url = $url; if(is_array($urls)) { $this->m_host = $urls[host]; if(!empty($urls[scheme])) $this->m_scheme = $urls[scheme]; if(!empty($urls[user])) $this->m_user = $urls[user]; if(!empty($urls[pass])) $this->m_pass = $urls[pass]; if(!empty($urls[port])) $this->m_port = $urls[port]; if(!empty($urls[path])) $this->m_path = $urls[path]; $this->m_urlpath = $this->m_path; if(!empty($urls[query])) { $this->m_query = $urls[query]; $this->m_urlpath .= ?.$this->m_query; } } } /** * 打开指定网址 */ function OpenUrl($url) { #重设各参数 $this->m_url = ; $this->m_urlpath = ; $this->m_scheme = http; $this->m_host = ; $this->m_port = 80; $this->m_user = ; $this->m_pass = ; $this->m_path = /; $this->m_query = ; $this->m_error = ; $this->m_httphead = ; $this->m_html = ; $this->Close(); #初始化系统 $this->PrivateInit($url); $this->PrivateStartSession(); } /** * 获得某操作错误的原因 */ public function printError() { echo 错误信息：.$this->m_error; echo 具体返回头：<br>; foreach($this->m_httphead as $k=>$v) { echo $k => $v <br>\r\n; } } /** * 判别用Get方法发送的头的应答结果是否正确 */ public function IsGetOK() { if( ereg(^2,$this->GetHead(http-state)) ) { return true; } else { $this->m_error .= $this->GetHead(http-state). - .$this->GetHead(http-describe).<br>; return false; } } /** * 看看返回的网页是否是text类型 */ public function IsText() { if (ereg(^2,$this->GetHead(http-state)) && eregi(^text,$this->GetHead(content-type))) { return true; } else { $this->m_error .= 内容为非文本类型<br>; return false; } } /** * 判断返回的网页是否是特定的类型 */ public function IsContentType($ctype) { if (ereg(^2,$this->GetHead(http-state)) && $this->GetHead(content-type) == strtolower($ctype)) { return true; } else { $this->m_error .= 类型不对 .$this->GetHead(content-type).<br>; return false; } } /** * 用 HTTP 协议下载文件 */ public function SaveToBin($savefilename) { if (!$this->IsGetOK()) return false; if (@feof($this->m_fp)) { $this->m_error = 连接已经关闭！; return false; } $fp = fopen($savefilename,w) or die(写入文件 $savefilename 失败！); while (!feof($this->m_fp)) { @fwrite($fp,fgets($this->m_fp,256)); } @fclose($this->m_fp); return true; } /** * 保存网页内容为 Text 文件 */ public function SaveToText($savefilename) { if ($this->IsText()) { $this->SaveBinFile($savefilename); } else { return ; } } /** * 用 HTTP 协议获得一个网页的内容 */ public function GetHtml() { if (!$this->IsText()) return ; if ($this->m_html!=) return $this->m_html; if (!$this->m_fp@feof($this->m_fp)) return ; while(!feof($this->m_fp)) { $this->m_html .= fgets($this->m_fp,256); } @fclose($this->m_fp); return $this->m_html; } /** * 开始 HTTP 会话 */ public function PrivateStartSession() { if (!$this->PrivateOpenHost()) { $this->m_error .= 打开远程主机出错!; return false; } if ($this->GetHead(http-edition)==HTTP/1.1) { $httpv = HTTP/1.1; } else { $httpv = HTTP/1.0; } fputs($this->m_fp,GET .$this->m_urlpath. $httpv\r\n); fputs($this->m_fp,Host: .$this->m_host.\r\n); fputs($this->m_fp,Accept: */*\r\n); fputs($this->m_fp,User-Agent: Mozilla/4.0+(compatible;+MSIE+6.0;+Windows+NT+5.2)\r\n); #HTTP1.1协议必须指定文档结束后关闭链接,否则读取文档时无法使用feof判断结束 if ($httpv==HTTP/1.1) { fputs($this->m_fp,Connection: Close\r\n\r\n); } else { fputs($this->m_fp,\r\n); } $httpstas = fgets($this->m_fp,256); $httpstas = split( ,$httpstas); $this->m_httphead[http-edition] = trim($httpstas[0]); $this->m_httphead[http-state] = trim($httpstas[1]); $this->m_httphead[http-describe] = ; for ($i=2;$i<count($httpstas);$i++) { $this->m_httphead[http-describe] .= .trim($httpstas[$i]); } while (!feof($this->m_fp)) { $line = str_replace(\,,trim(fgets($this->m_fp,256))); if($line == ) break; if (ereg(:,$line)) { $lines = split(:,$line); $this->m_httphead[strtolower(trim($lines[0]))] = trim($lines[1]); } } } /** * 获得一个Http头的值 */ public function GetHead($headname) { $headname = strtolower($headname); if (isset($this->m_httphead[$headname])) { return $this->m_httphead[$headname]; } else { return ; } } /** * 打开连接 */ public function PrivateOpenHost() { if ($this->m_host==) return false; $this->m_fp = @fsockopen($this->m_host, $this->m_port, &$errno, &$errstr,10); if (!$this->m_fp){ $this->m_error = $errstr; return false; } else { return true; } } /** * 关闭连接 */ public function Close(){ @fclose($this->m_fp); } } #两种使用方法，分别如下： #打开网页 $httpdown = new HttpDownload(); $httpdown->OpenUrl(下载文件 $file = new HttpDownload(); # 实例化类 $file->OpenUrl(远程文件地址 $file->SaveToBin(rust020.pdf); # 保存路径及文件名 $file->Close(); # 释放资源 ?>

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　　希望本文所述对大家PHP程序设计有所帮助。