Help with Threads for a webserver

Question

That is the main class of my webserver. The problem is that after executing one petition the server closes with exit status 1. Normally that should never happens as it does not happen at the single-threaded server. Any suggestions ??
Also do i have to impement monitors, meaning syncronized functions to monitor buffers and some static variables ?
This is my first program impementing threads so really i do not experience over it
package jhttp_server;
import java.io.*;
import java.net.*;
import java.lang.*;
* <p>Title: JHTTP_server</p>
* <p>Description: A simple HTTP server implemented with Java</p>
* <p>Copyright: Copyright (c) 2004 - Lisenced under GPL</p>
* <p>Company: Universidad Rey Juan Carlos</p>
* @author Panayiotis Papadopoulos -> [email protected]
* @version 0.1
public class jserver {
static ServerSocket serverSocket = null;
static PrintWriter out;
static BufferedReader in;
static Socket client = null;
static short i=0;
static int port;
static boolean newSock=true;
public static void main(String[] args) throws IOException {
port = Integer.valueOf(args[0]).intValue();
try {
     serverSocket = new ServerSocket(port);
catch (IOException e) {
     System.out.println("Must Enter a port number");
System.out.println("|------------------------------------------------------------------------|");
System.out.println("|JHTTP Server initialized and accepting connections on port:" +
serverSocket.getLocalPort()+"\t |");
System.out.println("|------------------------------------------------------------------------|");
while(true){
while (i < 5) {
i++;
try {
//Creating if needed a new socket where the clients listens
if (newSock) {
client = serverSocket.accept();
in = new BufferedReader(new InputStreamReader(client.getInputStream()));
out = new PrintWriter(client.getOutputStream());
System.out.println("LOG: Client is listening on port: "+client.getPort());
//Here the server creates a new thread for the petition
petition newPet = new petition();
newPet.T.start();
} // try- create input and output buffers
catch (UnknownHostException e) {
System.err.println("JHTTP Server could establish a connection. Exiting...");
catch (IOException e) {
System.err.println("Could not get I/O for the connection to client.");
} //try - create client sockets, wait and attend connection
} //while 5 petitions
System.out.println("Session Closed. 5 continious petitions served.");
out.close();
in.close();
client.close();
newSock = true;
System.gc();
i=0;
} // while - forever
}// -------------------main-------------------
}// jserver - main class of JHTTP server project
class petition implements Runnable {
Thread T;
petition () {
T = new Thread(this);
T.start();
public void run() {
try {
//Analyse petition
Petition_Analysis.Analyse_Petition(jserver.in);
//Then Attend it
if (Petition_Analysis.pt.Version.equals("v10"))
Http_10.Attend_Petition(Petition_Analysis.pt, jserver.out, extra.detectConnectionAlive());
else if (Petition_Analysis.pt.Version.equals("v11"))
Http_11.Attend_Petition(Petition_Analysis.pt, jserver.out, extra.detectClose());
else {
jserver.out.print("HTTP/1.0 400 Bad Request\r\n\r\n");
jserver.out.close();
jserver.in.close();
jserver.client.close();
jserver.newSock = true;
//The following function immediately prints the contents of the PrinterBuffer
jserver.out.flush();
System.gc();
catch (MalformedURLException murle) {
jserver.out.print("HTTP/1.0 400 Bad Request\r\n\r\n");
try { jserver.client.close(); }
catch(IOException ioe) { System.out.println(ioe); }
jserver.newSock = true;
catch (NullPointerException npe) {}
//try - analyse petition & attend it
catch (IOException ioe){
System.out.println(ioe);
} // -- run()
} // --class: thread

Answer 1

Use code tags when posting code.
Given that the code you presented does not call System.exit() I am not sure how it could be exiting with a value of 1.
When you accept a connection from a client the code should do nothing but pass the client socket off to a thread and then start that thread. It should not extract the streams - do that in the thread.
The in/out streams of the client socket should be wholly contained within the thread/Runnable. They do not belong to the class that holds the SockerServer.
Your catch blocks need to be reworked. The first one completely ignores the exception and prints out that a port number is needed. You should be printing the exception message at a minimum and right now you should be be doing a printStackTrace() as well. Additionally you are ignoring a null pointer exception and that is wrong.