/*
** Objektorienteeritud programmeerimine - pisikene WWW-server.
**
** NB! Tegemist on õppeotstarbelise näitega, mis ei ole 
** mõeldud reaalses elus kasutamiseks.
**
** NB! Seda serverit reaalses elus PALUN ärge kasutage.
**
** @author	Gunnar Kudrjavets [gk@aprote.ee]
** @version	0.1, 04.04.1999
** @since	JDK 1.0
*/

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

public class TinyHttpd {
	public static void main(String argv[]) throws IOException {
		if (argv.length == 1) {
			System.setSecurityManager(new TinyHttpdSecurityManager());
			ServerSocket listener = new ServerSocket(Integer.parseInt(argv[0]));
			while (true)
				new TinyHttpdConnection(listener.accept());
		} else {
			System.out.println("I need only one thing - port number!");
		}
	}
}

class TinyHttpdConnection extends Thread {
	Socket s;
	
	TinyHttpdConnection(Socket sServer) {
		s = sServer;
		setPriority(NORM_PRIORITY - 1);
		start();
	}

	public void run() {
		try {
			OutputStream out = s.getOutputStream();
			String strRequest = new DataInputStream(s.getInputStream()).readLine();
			System.out.println("Request: " + strRequest);

			StringTokenizer st = new StringTokenizer(strRequest);
			if ((st.countTokens() >= 2) && st.nextToken().equals("GET")) {
				if ((strRequest = st.nextToken()).startsWith("/"))
					strRequest = strRequest.substring(1);
				if (strRequest.endsWith("/") || strRequest.equals(""))
					strRequest = strRequest + "index.html";

				try {
					FileInputStream fis = new FileInputStream(strRequest);
					byte[] data = new byte[fis.available()];
					fis.read(data);
					out.write(data);
				}
				catch (FileNotFoundException e) {
					new PrintStream(out).println("404 Not Found");
				}
				catch (SecurityException e) {
					new PrintStream(out).println("403 Forbidden\n" + e);
				}
				s.close();
			} else {
				new PrintStream(out).println("400 Bad Request");
				s.close();
			}
		}
		catch (IOException e) {
			System.out.println("I/O error: " + e);
		}
	}
}

class TinyHttpdSecurityManager extends SecurityManager {
	public void checkAccess(Thread g) {};
	public void checkAccess(ThreadGroup tg) {};
	public void checkListen(int port) {};
	public void checkLink(String lib) {};
	public void checkPropertyAccess(String key) {};
	public void checkAccept(String host, int port) {};
	public void checkWrite(FileDescriptor fd) {};
	public void checkRead(FileDescriptor fd) {};

	public void checkRead(String s) {
		if (new File(s).isAbsolute() || (s.indexOf("..") != -1))
			throw new SecurityException("Access to file " + s + " denied.\nGo away!");
	}
}