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支持断点续传的PHP 下载远程文件类

WBOY
WBOY原创
2016-07-25 08:44:21895浏览

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 $m_html = "";
  19. /**
  20. * 初始化
  21. */
  22. public function PrivateInit($url){
  23. $urls = "";
  24. $urls = @parse_url($url);
  25. $this->m_url = $url;
  26. if(is_array($urls)) {
  27. $this->m_host = $urls["host"];
  28. if(!empty($urls["scheme"])) $this->m_scheme = $urls["scheme"];
  29. if(!empty($urls["user"])) $this->m_user = $urls["user"];
  30. if(!empty($urls["pass"])) $this->m_pass = $urls["pass"];
  31. if(!empty($urls["port"])) $this->m_port = $urls["port"];
  32. if(!empty($urls["path"])) $this->m_path = $urls["path"];
  33. $this->m_urlpath = $this->m_path;
  34. if(!empty($urls["query"])) {
  35. $this->m_query = $urls["query"];
  36. $this->m_urlpath .= "?".$this->m_query;
  37. }
  38. }
  39. }
  41. /**
  42. * 打开指定网址
  43. */
  44. function OpenUrl($url) {
  45. #重设各参数
  46. $this->m_url = "";
  47. $this->m_urlpath = "";
  48. $this->m_scheme = "http";
  49. $this->m_host = "";
  50. $this->m_port = "80";
  51. $this->m_user = "";
  52. $this->m_pass = "";
  53. $this->m_path = "/";
  54. $this->m_query = "";
  55. $this->m_error = "";
  56. $this->m_httphead = "" ;
  57. $this->m_html = "";
  58. $this->Close();
  59. #初始化系统
  60. $this->PrivateInit($url);
  61. $this->PrivateStartSession();
  62. }
  64. /**
  65. * 获得某操作错误的原因
  66. */
  67. public function printError() {
  68. echo "错误信息：".$this->m_error;
  69. echo "具体返回头：
    ";
  70. foreach($this->m_httphead as $k=>$v) {
  71. echo "$k => $v
    \r\n";
  72. }
  73. }
  75. /**
  76. * 判别用Get方法发送的头的应答结果是否正确
  77. */
  78. public function IsGetOK() {
  79. if( ereg("^2",$this->GetHead("http-state")) ) {
  80. return true;
  81. } else {
  82. $this->m_error .= $this->GetHead("http-state")." - ".$this->GetHead("http-describe")."
    ";
  83. return false;
  84. }
  85. }
  87. /**
  88. * 看看返回的网页是否是text类型
  89. */
  90. public function IsText() {
  91. if (ereg("^2",$this->GetHead("http-state")) && eregi("^text",$this->GetHead("content-type"))) {
  92. return true;
  93. } else {
  94. $this->m_error .= "内容为非文本类型
    ";
  95. return false;
  96. }
  97. }
  98. /**
  99. * 判断返回的网页是否是特定的类型
  100. */
  101. public function IsContentType($ctype) {
  102. if (ereg("^2",$this->GetHead("http-state")) && $this->GetHead("content-type") == strtolower($ctype)) {
  103. return true;
  104. } else {
  105. $this->m_error .= "类型不对 ".$this->GetHead("content-type")."
    ";
  106. return false;
  107. }
  108. }
  110. /**
  111. * 用 HTTP 协议下载文件
  112. */
  113. public function SaveToBin($savefilename) {
  114. if (!$this->IsGetOK()) return false;
  115. if (@feof($this->m_fp)) {
  116. $this->m_error = "连接已经关闭！";
  117. return false;
  118. }
  119. $fp = fopen($savefilename,"w") or die("写入文件 $savefilename 失败！");
  120. while (!feof($this->m_fp)) {
  121. @fwrite($fp,fgets($this->m_fp,256));
  122. }
  123. @fclose($this->m_fp);
  124. return true;
  125. }
  127. /**
  128. * 保存网页内容为 Text 文件
  129. */
  130. public function SaveToText($savefilename) {
  131. if ($this->IsText()) {
  132. $this->SaveBinFile($savefilename);
  133. } else {
  134. return "";
  135. }
  136. }
  138. /**
  139. * 用 HTTP 协议获得一个网页的内容
  140. */
  141. public function GetHtml() {
  142. if (!$this->IsText()) return "";
  143. if ($this->m_html!="") return $this->m_html;
  144. if (!$this->m_fp||@feof($this->m_fp)) return "";
  145. while(!feof($this->m_fp)) {
  146. $this->m_html .= fgets($this->m_fp,256);
  147. }
  148. @fclose($this->m_fp);
  149. return $this->m_html;
  150. }
  152. /**
  153. * 开始 HTTP 会话
  154. */
  155. public function PrivateStartSession() {
  156. if (!$this->PrivateOpenHost()) {
  157. $this->m_error .= "打开远程主机出错!";
  158. return false;
  159. }
  160. if ($this->GetHead("http-edition")=="HTTP/1.1") {
  161. $httpv = "HTTP/1.1";
  162. } else {
  163. $httpv = "HTTP/1.0";
  164. }
  165. fputs($this->m_fp,"GET ".$this->m_urlpath." $httpv\r\n");
  166. fputs($this->m_fp,"Host: ".$this->m_host."\r\n");
  167. fputs($this->m_fp,"Accept: */*\r\n");
  168. fputs($this->m_fp,"User-Agent: Mozilla/4.0+(compatible;+MSIE+6.0;+Windows+NT+5.2)\r\n");
  169. #HTTP1.1协议必须指定文档结束后关闭链接,否则读取文档时无法使用feof判断结束
  170. if ($httpv=="HTTP/1.1") {
  171. fputs($this->m_fp,"Connection: Close\r\n\r\n");
  172. } else {
  173. fputs($this->m_fp,"\r\n");
  174. }
  175. $httpstas = fgets($this->m_fp,256);
  176. $httpstas = split(" ",$httpstas);
  177. $this->m_httphead["http-edition"] = trim($httpstas[0]);
  178. $this->m_httphead["http-state"] = trim($httpstas[1]);
  179. $this->m_httphead["http-describe"] = "";
  180. for ($i=2;$i $this->m_httphead["http-describe"] .= " ".trim($httpstas[$i]);
  181. }
  182. while (!feof($this->m_fp)) {
  183. $line = str_replace("\"","",trim(fgets($this->m_fp,256)));
  184. if($line == "") break;
  185. if (ereg(":",$line)) {
  186. $lines = split(":",$line);
  187. $this->m_httphead[strtolower(trim($lines[0]))] = trim($lines[1]);
  188. }
  189. }
  190. }
  192. /**
  193. * 获得一个Http头的值
  194. */
  195. public function GetHead($headname) {
  196. $headname = strtolower($headname);
  197. if (isset($this->m_httphead[$headname])) {
  198. return $this->m_httphead[$headname];
  199. } else {
  200. return "";
  201. }
  202. }
  204. /**
  205. * 打开连接
  206. */
  207. public function PrivateOpenHost() {
  208. if ($this->m_host=="") return false;
  209. $this->m_fp = @fsockopen($this->m_host, $this->m_port, &$errno, &$errstr,10);
  210. if (!$this->m_fp){
  211. $this->m_error = $errstr;
  212. return false;
  213. } else {
  214. return true;
  215. }
  216. }
  218. /**
  219. * 关闭连接
  220. */
  221. public function Close(){
  222. @fclose($this->m_fp);
  223. }
  224. }
  226. #两种使用方法，分别如下：
  228. #打开网页
  229. $httpdown = new HttpDownload();
  230. $httpdown->OpenUrl("http://www.google.com.hk");
  231. echo $httpdown->GetHtml();
  232. $httpdown->Close();
  234. #下载文件
  235. $file = new HttpDownload(); # 实例化类
  236. $file->OpenUrl("http://www.ti.com.cn/cn/lit/an/rust020/rust020.pdf"); # 远程文件地址
  237. $file->SaveToBin("rust020.pdf"); # 保存路径及文件名
  238. $file->Close(); # 释放资源
  239. ?>
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断点续传, PHP


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