Java HttpURLConnection class

// Demonstrate HttpURLConnection. 
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.List;
import java.util.Map;
import java.util.Set;

public class Main {
   public static void main(String args[]) throws Exception {
      URL hp = new URL("http://www.google.com");

      HttpURLConnection hpCon = (HttpURLConnection) hp.openConnection();

      // Display request method.
      System.out.println("Request method is " + hpCon.getRequestMethod());

      // Display response code.
      System.out.println("Response code is " + hpCon.getResponseCode());

      // Display response message.
      System.out.println("Response Message is " + hpCon.getResponseMessage());

      // Get a list of the header fields and a set
      // of the header keys.
      Map<String, List<String>> hdrMap = hpCon.getHeaderFields();
      Set<String> hdrField = hdrMap.keySet();

      System.out.println("\nHere is the header:");

      // Display all header keys and values..
      for (String k : hdrField) {
         System.out.println("Key: " + k + "  Value: " + hdrMap.get(k));
      }//from   w w w .jav a  2  s  .c o m
   }
}