Java/Network Protocol/Proxy

Detect Proxy Settings for Internet Connection

 
import java.net.InetSocketAddress;
import java.net.Proxy;
import java.net.ProxySelector;
import java.net.URI;
import java.util.Iterator;
import java.util.List;
public class Main {
  public static void main(String[] args) throws Exception {
    System.setProperty("java.net.useSystemProxies", "true");
    List l = ProxySelector.getDefault().select(new URI("http://www.yahoo.ru/"));
    for (Iterator iter = l.iterator(); iter.hasNext();) {
      Proxy proxy = (Proxy) iter.next();
      System.out.println("proxy hostname : " + proxy.type());
      InetSocketAddress addr = (InetSocketAddress) proxy.address();
      if (addr == null) {
        System.out.println("No Proxy");
      } else {
        System.out.println("proxy hostname : " + addr.getHostName());
        System.out.println("proxy port : " + addr.getPort());
      }
    }
  }
}

Identify ourself to a proxy

 
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Properties;
public class Main{
  public static void main(String s[]) throws Exception{
    try {
      Properties systemSettings = System.getProperties();
      systemSettings.put("proxySet", "true");
      systemSettings.put("http.proxyHost", "proxy.mycompany.local");
      systemSettings.put("http.proxyPort", "80");
      URL u = new URL("http://www.java.ru");
      HttpURLConnection con = (HttpURLConnection) u.openConnection();
      sun.misc.BASE64Encoder encoder = new sun.misc.BASE64Encoder();
      String encodedUserPwd = encoder.encode("domain\\username:password".getBytes());
      con.setRequestProperty("Proxy-Authorization", "Basic " + encodedUserPwd);
      con.setRequestMethod("HEAD");
      System.out.println(con.getResponseCode() + " : " + con.getResponseMessage());
      System.out.println(con.getResponseCode() == HttpURLConnection.HTTP_OK);
    } catch (Exception e) {
      e.printStackTrace();
      System.out.println(false);
    }
  }
}

URL connection and proxy

 
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Properties;
public class Main{
  public static void main(String s[]) throws Exception{
    try {
      Properties systemSettings = System.getProperties();
      systemSettings.put("proxySet", "true");
      systemSettings.put("http.proxyHost", "proxy.mycompany.local");
      systemSettings.put("http.proxyPort", "80");
      URL u = new URL("http://www.java.ru");
      HttpURLConnection con = (HttpURLConnection) u.openConnection();
      sun.misc.BASE64Encoder encoder = new sun.misc.BASE64Encoder();
      String encodedUserPwd = encoder.encode("domain\\username:password".getBytes());
      con.setRequestProperty("Proxy-Authorization", "Basic " + encodedUserPwd);
      con.setRequestMethod("HEAD");
      System.out.println(con.getResponseCode() + " : " + con.getResponseMessage());
      System.out.println(con.getResponseCode() == HttpURLConnection.HTTP_OK);
    } catch (Exception e) {
      e.printStackTrace();
      System.out.println(false);
    }
  }
}