Referer原理與圖片防盜鏈實(shí)現(xiàn)方法詳解

!DOCTYPE html>
html>
head>
  meta charset="utf-8">
  meta http-equiv="X-UA-Compatible" content="IE=edge">
  title>/title>
  link rel="stylesheet" href="">
/head>
body>
  !--引用一張百度貼吧的圖片-->
  img src="http://imgsrc.baidu.com/forum/pic/item/03a4462309f79052204229be04f3d7ca7acbd5d5.jpg"/>
/body>
/html>

?php
/**
 * 下載圖片
 * @author webbc
 */
require './Http.class.php';//這個(gè)類是我自己封裝的一個(gè)用于HTTp請(qǐng)求的類
$http = new Http("http://localhost/booledu/http/apple.jpg");
//$http->setHeader('Referer:http://tieba.baidu.com/');//設(shè)置referer頭
$res = $http->get();
$content = strstr($res,"\r\n\r\n");
file_put_contents('./toutupian.jpg',substr($content,4));
echo "ok";
?>

?php
/**
 * Http請(qǐng)求類
 * @author webbc
 */
class Http{
  const CRTF = "\r\n";
  private $errno = -1;
  private $errstr = '';
  private $timeout = 5;
  private $url = null;//解析后的url數(shù)組
  private $version = 'HTTP/1.1';//http版本
  private $requestLine = array();//請(qǐng)求行信息
  private $header = array();//請(qǐng)求頭信息
  private $body = array();//請(qǐng)求實(shí)體信息
  private $fh = null;//連接端口后返回的資源
  private $response = '';//返回的結(jié)果
  //構(gòu)造函數(shù)
  public function __construct($url){
    $this->connect($url);
    $this->setHeader('Host:'.$this->url['host']);//設(shè)置頭信息
  }
  //通過(guò)URL進(jìn)行連接
  public function connect($url){
    $this->url = parse_url($url);//解析url
    if(!isset($this->url['port'])){
      $this->url['port'] = 80;
    }
    $this->fh = fsockopen($this->url['host'],$this->url['port'],$this->errno,$this->errstr,$this->timeout);
  }
  //設(shè)置請(qǐng)求行信息
  public function setRequestLine($method){
    $this->requestLine[0] = $method.' '.$this->url['path'].' '.$this->version;
  }
  //設(shè)置請(qǐng)求頭信息
  public function setHeader($headerLine){
    $this->header[] = $headerLine;
  }
  //設(shè)置請(qǐng)求實(shí)體信息
  public function setBody($body){
    $this->body[] = http_build_query($body);
  }
  //發(fā)送get請(qǐng)求
  public function get(){
    $this->setRequestLine('GET');//設(shè)置請(qǐng)求行
    $this->request();//發(fā)送請(qǐng)求
    $this->close();//關(guān)閉連接
    return $this->response;
  }
  //發(fā)送請(qǐng)求
  private function request(){
    //拼接請(qǐng)求的全部信息
    $reqestArr = array_merge($this->requestLine,$this->header,array(''),$this->body,array(''));
    $req = implode(self::CRTF,$reqestArr);
    //print_r($req);die;
    fwrite($this->fh,$req);//寫入信息
    //讀取
    while(!feof($this->fh)){
      $this->response .= fread($this->fh,1024);
    }
  }
  //發(fā)送post請(qǐng)求
  public function post($body = array()){
    //設(shè)置請(qǐng)求行
    $this->setRequestLine("POST");
    //設(shè)置實(shí)體信息
    $this->setBody($body);
    //設(shè)置Content-Type
    $this->setHeader('Content-Type:application/x-www-form-urlencoded');
    //設(shè)置Content-Length
    $this->setHeader('Content-Length:'.strlen($this->body[0]));
    //請(qǐng)求
    $this->request();
    $this->close();//關(guān)閉連接
    return $this->response;
  }
  //關(guān)閉連接
  public function close(){
    fclose($this->fh);
  }
}
//測(cè)試get
// $http = new Http("http://news.163.com/16/0915/10/C10ES2HA00014PRF.html");
// $result = $http->get();
// echo $result;
//測(cè)試post
/*set_time_limit(0);
$str = 'abcdefghijklmnopqrstuvwxyz0123456789';
while(true){
  $http = new Http("http://211.70.176.138/yjhx/message.php");
  $str = str_shuffle($str);
  $username = substr($str,0,5);
  $email = substr($str,5,10).'@qq.com';
  $content = substr($str,10);
  $message = "發(fā)表";
  $http->post(array('username'=>$username,'email'=>$email,'content'=>$content,'message'=>$message));
  //sleep(0.1);
}*/
?>