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支持断点续传的PHP 下载远程文件类

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Freigeben: 2016-07-25 08:44:21
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PHP 下载远程文件类,支持断点续传下载,代码内含有具体的调用说明。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。

  1. /**
  2. * 下载远程文件类支持断点续传
  3. */
  4. class HttpDownload {
  5. private $m_url = "";
  6. private $m_urlpath = "";
  7. private $m_scheme = "http";
  8. private $m_host = "";
  9. private $m_port = "80";
  10. private $m_user = "";
  11. private $m_pass = "";
  12. private $m_path = "/";
  13. private $m_query = "";
  14. private $m_fp = "";
  15. private $m_error = "";
  16. private $m_httphead = "" ;
  17. private $m_html = "";
  18. /**
  19. * 初始化
  20. */
  21. public function PrivateInit($url){
  22. $urls = "";
  23. $urls = @parse_url($url);
  24. $this->m_url = $url;
  25. if(is_array($urls)) {
  26. $this->m_host = $urls["host"];
  27. if(!empty($urls["scheme"])) $this->m_scheme = $urls["scheme"];
  28. if(!empty($urls["user"])) $this->m_user = $urls["user"];
  29. if(!empty($urls["pass"])) $this->m_pass = $urls["pass"];
  30. if(!empty($urls["port"])) $this->m_port = $urls["port"];
  31. if(!empty($urls["path"])) $this->m_path = $urls["path"];
  32. $this->m_urlpath = $this->m_path;
  33. if(!empty($urls["query"])) {
  34. $this->m_query = $urls["query"];
  35. $this->m_urlpath .= "?".$this->m_query;
  36. }
  37. }
  38. }
  39. /**
  40. * 打开指定网址
  41. */
  42. function OpenUrl($url) {
  43. #重设各参数
  44. $this->m_url = "";
  45. $this->m_urlpath = "";
  46. $this->m_scheme = "http";
  47. $this->m_host = "";
  48. $this->m_port = "80";
  49. $this->m_user = "";
  50. $this->m_pass = "";
  51. $this->m_path = "/";
  52. $this->m_query = "";
  53. $this->m_error = "";
  54. $this->m_httphead = "" ;
  55. $this->m_html = "";
  56. $this->Close();
  57. #初始化系统
  58. $this->PrivateInit($url);
  59. $this->PrivateStartSession();
  60. }
  61. /**
  62. * 获得某操作错误的原因
  63. */
  64. public function printError() {
  65. echo "错误信息:".$this->m_error;
  66. echo "具体返回头:
    ";
  67. foreach($this->m_httphead as $k=>$v) {
  68. echo "$k => $v
    \r\n";
  69. }
  70. }
  71. /**
  72. * 判别用Get方法发送的头的应答结果是否正确
  73. */
  74. public function IsGetOK() {
  75. if( ereg("^2",$this->GetHead("http-state")) ) {
  76. return true;
  77. } else {
  78. $this->m_error .= $this->GetHead("http-state")." - ".$this->GetHead("http-describe")."
    ";
  79. return false;
  80. }
  81. }
  82. /**
  83. * 看看返回的网页是否是text类型
  84. */
  85. public function IsText() {
  86. if (ereg("^2",$this->GetHead("http-state")) && eregi("^text",$this->GetHead("content-type"))) {
  87. return true;
  88. } else {
  89. $this->m_error .= "内容为非文本类型
    ";
  90. return false;
  91. }
  92. }
  93. /**
  94. * 判断返回的网页是否是特定的类型
  95. */
  96. public function IsContentType($ctype) {
  97. if (ereg("^2",$this->GetHead("http-state")) && $this->GetHead("content-type") == strtolower($ctype)) {
  98. return true;
  99. } else {
  100. $this->m_error .= "类型不对 ".$this->GetHead("content-type")."
    ";
  101. return false;
  102. }
  103. }
  104. /**
  105. * 用 HTTP 协议下载文件
  106. */
  107. public function SaveToBin($savefilename) {
  108. if (!$this->IsGetOK()) return false;
  109. if (@feof($this->m_fp)) {
  110. $this->m_error = "连接已经关闭!";
  111. return false;
  112. }
  113. $fp = fopen($savefilename,"w") or die("写入文件 $savefilename 失败!");
  114. while (!feof($this->m_fp)) {
  115. @fwrite($fp,fgets($this->m_fp,256));
  116. }
  117. @fclose($this->m_fp);
  118. return true;
  119. }
  120. /**
  121. * 保存网页内容为 Text 文件
  122. */
  123. public function SaveToText($savefilename) {
  124. if ($this->IsText()) {
  125. $this->SaveBinFile($savefilename);
  126. } else {
  127. return "";
  128. }
  129. }
  130. /**
  131. * 用 HTTP 协议获得一个网页的内容
  132. */
  133. public function GetHtml() {
  134. if (!$this->IsText()) return "";
  135. if ($this->m_html!="") return $this->m_html;
  136. if (!$this->m_fp||@feof($this->m_fp)) return "";
  137. while(!feof($this->m_fp)) {
  138. $this->m_html .= fgets($this->m_fp,256);
  139. }
  140. @fclose($this->m_fp);
  141. return $this->m_html;
  142. }
  143. /**
  144. * 开始 HTTP 会话
  145. */
  146. public function PrivateStartSession() {
  147. if (!$this->PrivateOpenHost()) {
  148. $this->m_error .= "打开远程主机出错!";
  149. return false;
  150. }
  151. if ($this->GetHead("http-edition")=="HTTP/1.1") {
  152. $httpv = "HTTP/1.1";
  153. } else {
  154. $httpv = "HTTP/1.0";
  155. }
  156. fputs($this->m_fp,"GET ".$this->m_urlpath." $httpv\r\n");
  157. fputs($this->m_fp,"Host: ".$this->m_host."\r\n");
  158. fputs($this->m_fp,"Accept: */*\r\n");
  159. fputs($this->m_fp,"User-Agent: Mozilla/4.0+(compatible;+MSIE+6.0;+Windows+NT+5.2)\r\n");
  160. #HTTP1.1协议必须指定文档结束后关闭链接,否则读取文档时无法使用feof判断结束
  161. if ($httpv=="HTTP/1.1") {
  162. fputs($this->m_fp,"Connection: Close\r\n\r\n");
  163. } else {
  164. fputs($this->m_fp,"\r\n");
  165. }
  166. $httpstas = fgets($this->m_fp,256);
  167. $httpstas = split(" ",$httpstas);
  168. $this->m_httphead["http-edition"] = trim($httpstas[0]);
  169. $this->m_httphead["http-state"] = trim($httpstas[1]);
  170. $this->m_httphead["http-describe"] = "";
  171. for ($i=2;$i $this->m_httphead["http-describe"] .= " ".trim($httpstas[$i]);
  172. }
  173. while (!feof($this->m_fp)) {
  174. $line = str_replace("\"","",trim(fgets($this->m_fp,256)));
  175. if($line == "") break;
  176. if (ereg(":",$line)) {
  177. $lines = split(":",$line);
  178. $this->m_httphead[strtolower(trim($lines[0]))] = trim($lines[1]);
  179. }
  180. }
  181. }
  182. /**
  183. * 获得一个Http头的值
  184. */
  185. public function GetHead($headname) {
  186. $headname = strtolower($headname);
  187. if (isset($this->m_httphead[$headname])) {
  188. return $this->m_httphead[$headname];
  189. } else {
  190. return "";
  191. }
  192. }
  193. /**
  194. * 打开连接
  195. */
  196. public function PrivateOpenHost() {
  197. if ($this->m_host=="") return false;
  198. $this->m_fp = @fsockopen($this->m_host, $this->m_port, &$errno, &$errstr,10);
  199. if (!$this->m_fp){
  200. $this->m_error = $errstr;
  201. return false;
  202. } else {
  203. return true;
  204. }
  205. }
  206. /**
  207. * 关闭连接
  208. */
  209. public function Close(){
  210. @fclose($this->m_fp);
  211. }
  212. }
  213. #两种使用方法,分别如下:
  214. #打开网页
  215. $httpdown = new HttpDownload();
  216. $httpdown->OpenUrl("http://www.google.com.hk");
  217. echo $httpdown->GetHtml();
  218. $httpdown->Close();
  219. #下载文件
  220. $file = new HttpDownload(); # 实例化类
  221. $file->OpenUrl("http://www.ti.com.cn/cn/lit/an/rust020/rust020.pdf"); # 远程文件地址
  222. $file->SaveToBin("rust020.pdf"); # 保存路径及文件名
  223. $file->Close(); # 释放资源
  224. ?>
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断点续传, PHP


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