getheaders.java

this gives details of the network programming

// Sample Java code - uses URL object to retreive a web page
//
// Looks for a url on the command line, prints out some headers that
//   are sent back by the server when fetching the URL
// Uses URLConnection object.

import java.net.*;
import java.io.*;
import java.util.*;	// need for Date object

public class GetHeaders {

    public static void main(String[] args)
    throws IOException, MalformedURLException{
	if (args.length!=1) {
	    System.out.println("You need to specify a URL");
	    System.exit(0);
	}

	URL u = new URL(args[0]);
	URLConnection uc = u.openConnection();
	//	BufferedReader r = new BufferedReader(new InputStreamReader ( u.openStream()));
	//	String s;
	//	while (	(s = r.readLine()) != null) {
	//	    System.out.println(s);
	//	}
	System.out.println("Content-type: " + uc.getContentType());
	System.out.println("Content-encoding: "+ uc.getContentEncoding());
	System.out.println("Content-length: "+ uc.getContentLength());

	// This doesn't do what we want, since getLastModified returns
	//   a long (number of ms since Jan 1, 1970).
	System.out.println("Last-modified: "+ uc.getLastModified());

	// This will do it right 
	System.out.println("Last-modified: "+ new Date(uc.getLastModified()));
    }
}