Thread: Run() method of runnable function has no access to data members?

I'm trying to make a server-client based TicTacToe game, and here I'm just starting off with the raw, raw basics.

The "client" will be executed in a thread. So, it implements runnable and has a Run() function.

I want to print the board during this run function.....but it claims that my board hasn't been initialized!!!

I've bolded the "board.printBoard()" command in the two parts that I have it in my code. The first part is part of the constructor, and it prints the board with no problem.

Once I enter the run() function, however, it started throwing exceptions all of a sudden for no apparent reason. What's going on here?

Here's the error message:

HTML Code:

Let's try to print the board
Exception in thread "main" java.lang.NullPointerException
        at TTTClient.run(TTTClient.java:53)
        at TTTClient.<init>(TTTClient.java:47)
        at TTTClient.main(TTTClient.java:27)

And here's the code.

Thanks in advance for the help.

import java.io.*;
import java.net.*;
import java.util.concurrent.*;
import java.util.Scanner;
 
 
public class TTTClient implements Runnable
{
	private char mySymbol;
	private boolean myTurn;
	private final char X_SYMBOL = 'X';
	private final char O_SYMBOL = 'O';
 
	private Board board;
	private Socket connection;
 
	private DataInputStream inpFromServer;
	private DataOutputStream outToServer;
 
	public static void main(String[] args)
	{
		TTTClient player = new TTTClient();	
	}
 
	public TTTClient()
	{
		Board board = new Board();
		[B]board.printBoard();[/B]
 
		try
		{
			connection = new Socket("localhost", 9821);
 
			inpFromServer = new DataInputStream(connection.getInputStream());
                        outToServer = new DataOutputStream(connection.getOutputStream());
		}
		catch (IOException ex)
		{
			System.err.println(ex);
		}
 
		run();
	}
 
	public void run()
	{
		System.out.println("Let's try to print the board");
		[B]board.printBoard();[/B]
		System.out.println("The board should have been printed");
         }
}

Well....the variable was the 'board'.

When I backtrack, I see that the 'board' was set to a 'new Board', thus eliminating its null value.

I verified this by calling the printBoard method, via 'board', in the constructor (right after board = new Board()).

Hence, the board is no longer null.

Yet, when I enter the run function, it magically becomes null once again. I have no idea why. As a data member of my TTTClient class, I see no reason why initializing it in the constructor wouldn't initialize it for the rest of the class

Board board = new Board(); creates a new variable local to the constructor.
Are you sure this is what you meant to do?

Ah, stupid mistake.

Thanks for the help!!!