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("http://www.google.com.hk");echo $httpdown->GetHtml();$httpdown->Close();#下载文件$file = new HttpDownload(); # 实例化类$file->OpenUrl("http://www.ti.com.cn/cn/lit/an/rust020/rust020.pdf"); # 远程文件地址$file->SaveToBin("rust020.pdf"); # 保存路径及文件名$file->Close(); # 释放资源?>