PHP下载远程文件类源码，带详细注释，还支持断点续传
作者：袖梨
2022-06-24
程序主要是使用 HTTP 协议下载文件，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，可以有两种使用方法，具体请下载查看源码。
| 代码如下 | 复制代码 |
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/** * 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： "; foreach($this->m_httphead as $k=>$v) { echo "$k => $v rn"; } } /** * 判别用Get方法发送的头的应答结果是否正确 */ public function IsGetOK() { if( ereg("^2",$this->GetHead("http-state")) ) { return true; } else { $this->m_error .= $this->GetHead("http-state")." - ".$this->GetHead("http-describe")." "; 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 { $this->m_error .= "内容为非文本类型 "; return false; } } /** * 判断返回的网页是否是特定的类型 */ public function IsContentType($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")." "; 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." $httpvrn"); fputs($this->m_fp,"Host: ".$this->m_host."rn"); fputs($this->m_fp,"Accept: */*rn"); fputs($this->m_fp,"User-Agent: Mozilla/4.0+(compatible;+MSIE+6.0;+Windows+NT+5.2)rn"); #HTTP1.1协议必须指定文档结束后关闭链接,否则读取文档时无法使用feof判断结束 if ($httpv=="HTTP/1.1") { fputs($this->m_fp,"Connection: Closernrn"); } else { fputs($this->m_fp,"rn"); } $httpstas = fgets($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;$i } while (!feof($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 ?> |
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