java程序如何穿透带有密码验证的代理

网上也有一些文章但是大多数涉及带有授权验证的proxy都有问题，主要问题就是出在对Authenticator.setDefault的使用，以及base64编码的问题上代码是最没有二义性的文档，实现原理不再解释，请看代码去体会。如果转载请注明代码出处。

package org.chimae.net;

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStream;

import java.io.InputStreamReader;

import java.net.Authenticator;

import java.net.HttpURLConnection;

import java.net.PasswordAuthentication;

import java.net.URL;

/**

* @author chimae@cnjsp.org

*/

public class ProxyConnTest {

public static void initProxy(String host, int port, final String username,

final String password) {

Authenticator.setDefault(new Authenticator() {

protected PasswordAuthentication getPasswordAuthentication() {

return new PasswordAuthentication(username,

new String(password).toCharArray());

}

});

System.setProperty(\"http.proxyType\", \"4\");

System.setProperty(\"http.proxyPort\", Integer.toString(port));

System.setProperty(\"http.proxyHost\", host);

System.setProperty(\"http.proxySet\", \"true\");

}

public static void main(String[] args) throws IOException {

String url = \"http://java.sun.com/\";

String proxy = \"yourProxy\";

int port =8080;

String username =\"username\";

String password =\"password\";

String curLine = \"\";

String content = \"\";

URL server = new URL(url);

initProxy(proxy,port,username,password);

HttpURLConnection connection = (HttpURLConnection)server.openConnection();

connection.connect();

InputStream is = connection.getInputStream();

BufferedReader reader = new BufferedReader(new InputStreamReader(is));

while ((curLine = reader.readLine()) != null) {

content += curLine;

}

System.out.println(\"content= \" + content);

is.close();

}

}