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();
}

}