Comparing variables :(

Question

I am going crazy. I am a Java beginner:
if(numOfConnections < alowConections)
this line is not working properly while i run this little server of mine. It should limit connections, and even thought number should be less then 3 (in this case) it alows 3 connections. other thing is when client has disconnected by closing the telnet window the numOfConnections is decremented, but then it wount let 3rd connection to be made.. what's going on? this is crazy.
P.S. any other advise regarding the code?
import java.net.*;
import java.io.*;
public class Server {
     ServerSocket sock = null;
     static int numOfConnections = 0;
     static final int alowConections = 3;
     public Server() {
          try {
               sock = new ServerSocket(4413);
          } catch(Exception e) {
               System.out.println("E" + e.getMessage());
          try {
               while(true) {
                    if(numOfConnections < alowConections) {
                         new MultiServer(sock.accept()).start();
                         numOfConnections += 1;
                         System.out.println("Number of clients connected: " + numOfConnections);
                    } else {
                         new RegectServer(sock.accept()).start();
          } catch (Exception e) {
               System.out.println(e.getMessage());
     public static void main(String[] args) {
          Server serve = new Server();
     public static void printNumOfConnections() {
          System.out.println("Number of clients connected: " + numOfConnections);
class MultiServer extends Thread {
     Socket client;
     MultiServer(Socket cl) {
          client = cl;
     public void run() {
          try {
               InputStreamReader isr = new InputStreamReader(client.getInputStream());
               BufferedReader is = new BufferedReader(isr);
               PrintWriter os = new PrintWriter(new
                    BufferedOutputStream(client.getOutputStream()), false);
               String outLine = "Welcome to spilo Server!";
               os.println(outLine);
               os.flush();
               while(true) {
                    String inLine = is.readLine();
                    if(inLine == "exit" | inLine == null) break;
                    os.println(inLine);
                    os.flush();
               Server.numOfConnections -= 1;
               Server.printNumOfConnections();
               os.close();
               is.close();
               client.close();
          } catch(IOException e) {
               System.out.println(e.getMessage());
class RegectServer extends Thread{
     Socket client;
     RegectServer(Socket cl) {
          client = cl;
     public void run() {
          try {
               PrintWriter os = new PrintWriter(new
                         BufferedOutputStream(client.getOutputStream()), false);
               String outLine = "Server Full, Bye";
               os.println(outLine);
               os.flush();
               os.close();
               client.close();
          } catch(IOException e) {
               System.out.println("Error");
}

Answer 1

if(numOfConnections < alowConections)
this line is not working properly while i run this
little server of mine. It should limit connections,
and even thought number should be less then 3 (in
this case) it alows 3 connections. That's just fine, you defined it this way. E.g. when there are 2 connections, the check will result in true as 2 < 3. If you want only 2 connections, reduce "alowConections" to 2.
other thing is
when client has disconnected by closing the telnet
window the numOfConnections is decremented, but then
it wount let 3rd connection to be made.. what's going
on? this is crazy.I bet the line " Server.numOfConnections -= 1;" is not reached as an IOException is thrown when you read from/write to a closed connection; add this line into a finally clause, for instance.
P.S. any other advise regarding the code?Yes, som quick ones:
Don't do your main job in the constructor, that's no good style.
Also: you catch and only write out possible exceptions when trying to create the server socket -- the program shouldn't go on if this socket can't be created.