New to Java Thread Help

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


public class server2
{



  public static int fibonacci (int number)
  {
    if ( number == 0 || number == 1 )
       return ( number );
    else
       return (fibonacci(number - 1) + fibonacci (number - 2));
  }

  public void main (String[] args)
  {
    int selection = -1;
    int sock_choice = 7001;
    int fib = -1;
    int n = -1;
    long time = -1;
    String user_input;
    try
       {
        ServerSocket sock = new ServerSocket (sock_choice);
        // now listen for connections
        while (true)
        {
           Socket client = sock.accept();
           PrintWriter pout = new
            PrintWriter(client.getOutputStream(), true);
           pout.println("Make a selection from the menu: \r");
           pout.println("1) Time and date \r");
           pout.println("2) Random saying \r");
           pout.println("3) Fibonacci sequence for n \r");
           pout.println("4) Quit \r");
          BufferedReader client_in =
            new BufferedReader (new InputStreamReader(client.getInputStream()));
         user_input = client_in.readLine();
         selection = Integer.parseInt(user_input);
         if (selection == 1)
          {
           pout.println(new java.util.Date() .toString());
            // write the date to the socket
           }
         else if (selection == 2 )
           {
            pout.println("RANDOM STATEMENT HERE");
            time = System.currentTimeMillis();
            time = time % 10;
            if (time <= 2 )
             {
               pout.println("With the lights out it's less dangerous \r");
             }
            else if (time > 2 && time <= 5)
             {
               pout.println("God is in the TV \r");
             }
            else if (time > 5 && time <= 8)
             {
               pout.println("I never thought I would say this, I want to program in C++ \r");
             }
            else
             {
               pout.println("Your random number is greater than 8, couldn't think of anything else \r");
             }
           }
         else if (selection == 3)
          {
           pout.println("FIBONACCI SEQUENCE HERE \r");
           pout.println ("ENTER A NUMBER TO DISPLAY THE FIBONACCI SEQUENCE \r");
           BufferedReader client_in2 =
               new BufferedReader (new InputStreamReader(client.getInputStream()));
           user_input = client_in2.readLine();
           n = Integer.parseInt(user_input);
           int x= fibonacci(n);
           {

             pout.println("The Fibonacci of \r"); pout.println( n ); pout.println ("is \r"); pout.println( x );

           }

          }
         else if (selection == 4)
          {
           pout.println("EXITING");
          }
         else
           {
            pout.println("MAKE A SELECTION FROM THE MENU");
           }
           client.close();
         }
        }
    catch (IOException ioe)
    {
        System.err.println(ioe);
    }
  }
}