Multi-threaded HTTP Server

My earlier post on creating a single threaded HTTP/1.0 Server using Java gave an idea about how to implement an HTTP server. This post is an extension to the same program. I have implemented a Multi-threaded version of the same server. The source code is given below.

Implementation
A new thread is spawned upon receiving a connection request from a client. This socket is used to transfer data between these two end-systems. Since the server implements HTTP/1.0, the connection is terminated after the request is satisfied by the server.

The code is available here.

Multi-threaded server

/*
 * Coded By: Rahul Krishnan
 */

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

class MTServer implements Runnable {
 // Socket available to all the methods in the class.
 private Socket connectionSocket;
 
 // Constructor.
 MTServer (Socket sock) {
  connectionSocket = sock;
 }
 
 // Main starts here.
 public static void main(String argv[]) throws Exception {  
  // Listen to the client connection.
  ServerSocket listenSocket = new ServerSocket(4444);
  
  // Spawn threads for all the new connections.
  while (true) {
   Socket connectionSocket = listenSocket.accept();
   Thread T = new Thread(new MTServer(connectionSocket));
   T.start();
  }
 }
 
 // Thread code.
 public void run() {
  String httpReqMsg = null;   // Strores the request from client.
  String fileName = null;    // Stores the file name to be fetched.
  BufferedReader inFromClient = null; // Input Stream - from the client.
  DataOutputStream outToClient = null;// Output Stream - to client.
  FileInputStream inFile = null;  // Input Stream - from file.
  
  try {
   inFromClient = new BufferedReader(
     new InputStreamReader(connectionSocket.getInputStream()));
   outToClient = new DataOutputStream(
     connectionSocket.getOutputStream());
   
   // Read the request from client.
   httpReqMsg = inFromClient.readLine();
  }
  catch (IOException exception) {
   exception.printStackTrace();
  }
   
  StringTokenizer tokenizedLine = new StringTokenizer(httpReqMsg);
  // Extract the file name.
  if (tokenizedLine.nextToken().equals("GET")) {
   fileName = tokenizedLine.nextToken();
   
   // Process the file name.
   if (fileName.startsWith("/") == true) {
    // Extract the portion after '/' in the file name.
    fileName = fileName.substring(1);
   }
   
   // Access the file.
   File file = new File(fileName);
   int numOfBytes = (int) file.length();
   
   byte[] fileInBytes = new byte[numOfBytes];
   
   try {
    inFile = new FileInputStream(fileName);
   }
   catch (FileNotFoundException exception) {
    exception.printStackTrace();
   }
   
   try {
    inFile.read(fileInBytes);
   }
   catch (IOException exception) {
    exception.printStackTrace();
   }
   
   try {
    // Server response message starts.
    outToClient.writeBytes("HTTP/1.0 200 OK\r\n");
   
    // Send the content type.
    if (fileName.endsWith(".jpg")) {
     outToClient.writeBytes("Content-Type: image/jpeg\r\n");
    }
    if (fileName.endsWith(".gif")) {
     outToClient.writeBytes("Content-Type: image/gif\r\n");
    }
    // Send the content length.
    outToClient.writeBytes("Content-Lenght: " + numOfBytes + "\r\n");
   
    // Important : comply with the HTTP reply format.
    outToClient.writeBytes("\r\n");
    // Write the file into the output stream.
    outToClient.write(fileInBytes, 0, numOfBytes);
    connectionSocket.close();
   }
   catch (IOException exception) {
    exception.printStackTrace();
   }
  }
 }
}