// File: TrivialWebServer.java (Module 13)
//
// Author: Rahul Simha
// Created: Nov 30, 2010
//
// A trivial webserver that only sends files from a single
// directory.

import java.net.*;
import java.io.*;

public class TrivialWebServer {

    public static void main (String[] argv)
    {
	try {
	    // Create a listening service for connections
	    // at the designated port number.
	    ServerSocket srv = new ServerSocket (40013);

	    while (true) {

		// When a connection is made, get the socket.
		// The method accept() blocks until then.
		System.out.println ("Webserver: waiting for a connection");
		Socket soc = srv.accept ();

		// At this stage, the connection will have been made.
		InetAddress remoteMachine = soc.getInetAddress();
		System.out.println ("Accepted a connection from " + remoteMachine);

		// We are going to both read and write. Start with reading.
		InputStream inStream = soc.getInputStream ();
		InputStreamReader isr = new InputStreamReader (inStream);
		LineNumberReader lnr = new LineNumberReader (isr);

		// For writing.
		OutputStream outStream = soc.getOutputStream ();
		PrintWriter pw = new PrintWriter (outStream);

		// First read the GET command.
		String command = lnr.readLine ();

		// Remove "GET " so that the remainder is the file name.
		String fileName = command.substring (4);      

		// Now serve the file back.
		FileReader fr = new FileReader (fileName);
		LineNumberReader lnr2 = new LineNumberReader (fr);
		String line = lnr2.readLine ();
		while (line != null) {
		    pw.println (line);
		    line = lnr2.readLine ();
		}

		// Close the streams.
		pw.close ();
		lnr.close ();
		soc.close ();

	    } // end-while
	
	}
	catch (IOException e) { System.out.println (e); }
    }
}