百科地址：http://baike.baidu.com/view/868685.htm
官网地址：http://fiddler2.com/
firefox的fidder插件
而java程序需要设置proxy才能生效：
String url="http://www.zuidaima.com/";
Proxy proxy = new Proxy(java.net.Proxy.Type.HTTP,new InetSocketAddress("127.0.0.1", 8888));
URL serverUrl = new URL(url);
HttpURLConnection conn = (HttpURLConnection) serverUrl.openConnection(proxy);
详细代码请下载:http://www.zuidaima.com/code/file/1429831521764352.htm?dir=/1429831521764352.java