Java示例查找代理设置1

import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Properties;
import java.net.InetSocketAddress;
import java.net.Proxy;
import java.net.ProxySelector;
import java.net.URI;

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.mycompany1.local");
         systemSettings.put("http.proxyPort", "80");

         URL u = new URL("http://www.google.com");
         HttpURLConnection con = (HttpURLConnection)u.openConnection();
         System.out.println(con.getResponseCode() + " : " + con.getResponseMessage());
         System.out.println(con.getResponseCode() == HttpURLConnection.HTTP_OK);
      } catch (Exception e) {
         e.printStackTrace();
         System.out.println(false);
      }
      System.setProperty("java.net.useSystemProxies", "true");
      Proxy proxy = (Proxy) ProxySelector.getDefault().select(new URI(
         "http://www.yahoo.com/")).iterator().
      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());
      }
   }
}