浏览器拦截跨域请求处理方法（firebug报错，同源策略不允许读取XXX上的远程资源）

1. 如果可以使用get请求的话，可以使用jsonp。十分简单的方法。

2. 如果要使用post请求域名不相同的资源的话，可以用cors跨域。

以下两项缺一不可：

      1） 在被请求的项目根目录（root下）下放以下文件

      crossdomain.xml

<?xml version="1.0"?>
<!DOCTYPE cross-domain-policy SYSTEM "./cross-domain-policy.dtd">
<cross-domain-policy> <site-control permitted-cross-domain-policies="all" />
    <allow-access-from domain="*" />
    <allow-http-request-headers-from domain="*" headers="*"/>
</cross-domain-policy>

     cross-domain-policy.dtd

<?xml version="1.0" encoding="ISO-8859-1"?>
<!-- Adobe DTD for cross-domain policy files -->
<!-- Copyright (c) 2008-2009, Adobe Systems Inc. -->

<!ELEMENT cross-domain-policy (site-control?,allow-access-from*,allow-http-request-headers-from*,allow-access-from-identity*)>

<!ELEMENT site-control EMPTY>
<!ATTLIST site-control permitted-cross-domain-policies (all|by-content-type|by-ftp-filename|master-only|none) #REQUIRED>

<!ELEMENT allow-access-from EMPTY>
<!ATTLIST allow-access-from domain CDATA #REQUIRED>
<!ATTLIST allow-access-from to-ports CDATA #IMPLIED>
<!ATTLIST allow-access-from secure (true|false) "true">

<!ELEMENT allow-http-request-headers-from EMPTY>
<!ATTLIST allow-http-request-headers-from domain CDATA #REQUIRED>
<!ATTLIST allow-http-request-headers-from headers CDATA #REQUIRED>
<!ATTLIST allow-http-request-headers-from secure (true|false) "true">

<!ELEMENT allow-access-from-identity (signatory)>

<!ELEMENT signatory (certificate)>

<!ELEMENT certificate EMPTY>
<!ATTLIST certificate fingerprint CDATA #REQUIRED>
<!ATTLIST certificate fingerprint-algorithm CDATA #REQUIRED>

<!-- End of file. -->

       测试从http://domain:port/crossdomain.xml可访问到这两个xml。

     2.）被请求的目标在返回时需加Responseheader   Access-Control-Allow-Origin

        response.setHeader("Access-Control-Allow-Origin", "*");

       后面的*可以是请求方的域名。

再次尝试，firebug控制台不会报错了~