巧妙解决AJAX跨域问题

<?php

/**
* ajax proxy
* ajax跨域解决办法
* @author  suconghou <[email protected]>
* @version v1.1
* @blog http://blog.suconghou.cn
* @update 2014.2.26
* @ 修正了get时忽略了端口号的问题
*/
class ajax 
{
 
    private $url; ///真实的ajax地址
    private $get;
    private $post;
    private $get_string;
    private $post_string;
    private $result;

    function __construct()
    {
        isset($_REQUEST['url'])||exit('no available url');
        $this-> url=$_REQUEST['url'];
        foreach ($_GET as $key => $value)
        {
            if($key=='url')continue;
            $this-> get[$key]=$value;
        }
        foreach ($_POST as $key => $value)
        {
            if($key=='url')continue;        
            $this-> post[$key]=$value;
        }
        if(!empty($this-> get))
        {
            $this-> get_string=$this->implode_with_key($this-> get);
        }
        if(!empty($this-> post))
        {
             $this-> post_string=$this->implode_with_key($this-> post);
        }
        //$this-> debug();
        $this-> ajax();
      
    }

    function debug($debug=1)
    {
        
            var_dump($this-> get);
            var_dump($this-> post);
            var_dump($this-> get_string);
     

    }
    function ajax()
    {

        if (empty($this-> post))///没有post数据,但可能有get
        {
            $this->get();
        }
        else //可能有post,有get
        {
            $this->post();
        }
        echo $this-> result;

    }

    ///三种版本的post,get,优先使用curl
    function post()
    {
        if (extension_loaded('curl'))
        {   
            $url=$this->query_string();
            $ch=curl_init();
            curl_setopt_array($ch, array(CURLOPT_URL=>$url,CURLOPT_RETURNTRANSFER=>1,CURLOPT_POST=>1,CURLOPT_POSTFIELDS=>$this-> post_string));
            $this-> result=curl_exec($ch);
            curl_close($ch);
           

        }
        else if(function_exists('fsockopen'))
        {
            $parts = parse_url($this-> url);
            $fp= fsockopen($parts['host'],isset($parts['port']) ? $parts['port'] : 80,$errno, $errstr,10);
            if (!$fp) die("$errstr($errno)");
            $url=$this->query_string(1);
            $out='POST '.$url."\r\nContent-type: application/x-www-form-urlencoded\r\n"."Content-length: " . strlen($this-> post_string) . "\r\nConnection: close\r\n\r\n".$this-> post_string;
            //exit($out);
            fwrite($fp,$out);

            while ($str = trim(fgets($fp, 4096)))
            {
                 $header .= $str;
            }
            while (!feof($fp))
            {
               $data.=fgets($fp, 4096);
            }

            $this-> result=$data;

            
        }
        else
        {
            $context = array(
            'http' => array(
            'method' => 'POST',
            'header' => 'Content-type: application/x-www-form-urlencoded\r\n' .                   
                        'Content-length:' . strlen($this-> post_string)+8,
            'content' =>$this-> post_string)
            );
            $stream_context = stream_context_create($context);
            $data = file_get_contents($this->query_string(), false, $stream_context);
            $this-> result=$data;

        }

    }
    function get()
    {

        if (extension_loaded('curl'))//已修正端口号问题
        {
            $ch=curl_init();           
            $url=$this->query_string();
           
            curl_setopt_array($ch, array(CURLOPT_URL=>$url,CURLOPT_RETURNTRANSFER=>1));
            $this-> result=curl_exec($ch);
            curl_close($ch);
          
        }
        else if(function_exists('fsockopen'))
        {
            $parts = parse_url($this-> url);
            $fp= fsockopen($parts['host'],isset($parts['port']) ? $parts['port'] : 80,$errno, $errstr,10);
            if (!$fp) die("$errstr($errno)"); 
            $url=$this->query_string(1);
            $out = 'GET ' . $url . "\r\nConnection: Close\r\n\r\n";
            fwrite($fp, $out);
            while ($str = trim(fgets($fp, 4096)))
            {
                 $header .= $str;
            }
            while (!feof($fp))
            {
               $data.=fgets($fp, 4096);
            }
            $this-> result=$data;
 
        }
        else
        {

            $url=$this->query_string();        
            $this-> result=file_get_contents($url);

           
        }


    }

    function implode_with_key($assoc, $inglue = '=', $outglue = '&')
    {
        $return = null;
        foreach ($assoc as $tk => $tv) $return .= $outglue.$tk.$inglue.$tv;
        return substr($return,1);
    }

    function query_string($type=0)
    {
        $parts = parse_url($this-> url);
        $host_port=$parts['host'];
        if($parts['port'])
        {
            $host_port.=':'.$parts['port'];
        }
      
        if (empty($parts['query']))
        {
           $parts['query']=$this-> get_string;
        }
        else
        {   
            if(!empty($this-> get_string))
            {
                $parts['query'].='&'.$this-> get_string;
            }
            
        }         
        if($type)
        {
            $url=$parts['path'].'?'.$parts['query']." HTTP/1.1\r\nHost: " . $host_port ; 
        }
        else
        {
            $url=$parts['scheme'].'://'.$host_port.$parts['path'].'?'.$parts['query'];   
        }
       //exit($url);
       return $url;

    }


}


$ajax=new ajax();

在发送AJAX时提交参数url给ajax.php文件,url为你想要发送异步请求的ajax页面.例如

var url="./ajax.php?url=http://my.oschain.net?a=1&b=2";
	$.get(url,{name:'11',pass:'11260',htm:'html'},function(data){
		$('#text').html(data);
	});
///此时会发送get数据 name,pass,htm到http://my.oschain.net?a=1&b=2,故发送get时,get数据可以写在url后面,也可以单独,并且url参数也可以单独.
///或者

var url="./ajax.php?url=http://127.0.0.2:8088/3.php?a=1&b=3";
	$.post(url,{name:'11',pass:'11260',htm:'html'},function(data){
		$('#text').html(data);
	});
///这样会发送get中的a,b post中的name,pass,htm
///并且无论get还是post,你都可以将url单独传送,不区分get和post,
///如
var url="./ajax.php";
	$.post(url,{url:'http://my.oschina.net/',name:'11',pass:'11260',htm:'html'},function(data){
		$('#text').html(data);
	});