使用阻塞队列传递变量

Question

目前我正在尝试让我的程序将变量xPos和yPos从ChessBoard类传递到makeMove()中的HumanPlayer方法。

但目前它只是在HumanPlayer中提供空指针异常。

这可以用BlockingQueues来完成，如果是这样，我做错了什么？

HumanPlayer

import java.util.*;
import java.util.concurrent.BlockingQueue;

public class HumanPlayer extends Player implements Runnable{
    private Scanner in;

    protected BlockingQueue<Integer> queue = null;
    int x;
    int y;


    public HumanPlayer(String n, Pieces p, Board b, Player o, BlockingQueue<Integer> queue) {
        super(n, p, b, o);
        this.queue = queue;
    }


    @Override
    public void run() {
        try{
             x =  queue.take();
             y =  queue.take();
        }
        catch (InterruptedException e){
            e.printStackTrace();
        }

    }

    public boolean makeMove() {
        // declare board and selected piece
        Board chess = getBoard();
        Piece selected;


        //take input of piece player wants to move
//      in = new Scanner(System.in);
//      System.out.println("Select Piece: "); 
//      System.out.print("x: ");
//      String inputX = in.nextLine().toUpperCase();
//      System.out.print("y: ");
//      String inputY = in.nextLine();
//      System.out.println(inputX+inputY);

//      //if one of the inputs is >1 length then return false to stop error
//      if (inputY.length()!=1 || inputX.length() !=1)
//          return false;

//      //change inputs to numbers to use in array
//      int x = (int)(inputX.charAt(0)-'A');
//      int y = (int)(inputY.charAt(0)-'0')-1;

        run();

        // if the input is in range of the board array select that piece if not return false
        if ( x<=7 && x>=0 && y<=7 && y>=0){             
            selected = chess.getPiece(x,y);
            System.out.println(x+""+y);
        }
        else
            return false;

        // check the piece selected is not null and is the players own piece
        if ((selected != null) 
                && (getPieces().getPiece(0).getColour() == selected.getColour() )) {
        }
        else 
            return false;

        // get the position the player wants to move the piece to
//      System.out.println("Select Move: ");
//      System.out.print("x: ");
//      String moveX = in.nextLine().toUpperCase();
//      System.out.print("y: ");
//      String moveY = in.nextLine();
//      System.out.println(moveX+moveY);

        // check the inputs length are > 1 to stop errors
//      if (moveY.length()!=1 || moveX.length() !=1)
//          return false;
//      //change inputs to ints for array
//      int mX = (int)(moveX.charAt(0)-'A');
//      int mY = (int)(moveY.charAt(0)-'0')-1;
        run();
        int mX = x;
        int mY = y;
        //check the inputs are not > 7 or less than 0
        if ( mX>7 || mX<0 || mY>7 || mY<0) {                
            return false;
        }
        //declare boolean and move
        boolean occupied = getBoard().occupied(mX, mY);
        Move requested = new Move(selected,x,y,mX,mY,occupied);

        //check if the move is and available move
        if ( selected.availableMoves().contains(requested) ){
            //delete the opponents piece if its taken
            if (occupied){
                Piece remove = chess.getPiece(mX,mY);
                chess.remove(mX, mY);
                getOpponent().getPieces().delete(remove);
            }
            // move the piece to desired position
            selected.setPosition(mX, mY);
            chess.setPosition(mX, mY, selected);
            chess.remove(x, y);         
            return true;
        }
        //return false if not and available move
        return false;
    }

}

器ChessBoard

import java.awt.*;
import java.awt.event.*;
import java.util.concurrent.BlockingQueue;

import javax.swing.*;

@SuppressWarnings("serial")
public class ChessBoard extends JFrame implements ActionListener, Runnable{
    JButton[][] squares;
    private int xPos;
    private int yPos;
    protected BlockingQueue<Integer> queue = null;
    public ChessBoard(BlockingQueue<Integer> queue){
        this.queue = queue;
        setSize(800,800);
        setTitle("chess");
        setResizable(false);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        Container contentPane = getContentPane();
        contentPane.setLayout(new GridLayout (8,8));
        squares = new JButton[8][8];
        Color lightBrown = new Color(222,184,135);
        Color Brown = new Color(167,71,20);
        for(int y=7; y>=0; y--){
            for(int x=0; x<8; x++){
                squares[x][y] = new JButton();
                squares[x][y].addActionListener(this);

                if ((x + y) % 2 == 0) {
                    squares[x][y].setBackground(Brown);
                } 
                else {
                    squares[x][y].setBackground(lightBrown);
                }  
                contentPane.add(squares[x][y]);
            }
        }
        setVisible(true);
    }

    public JButton getButton(int x, int y){
        return squares[x][y];           
    }
    @Override
    public void actionPerformed(ActionEvent e) {
        JButton selected = (JButton) e.getSource();
        for(int y=7; y>=0; y--){
            for(int x=0; x<8; x++){
                if( selected == squares[x][y]){
                    xPos = x;
                    yPos = y;   
                    System.out.println(xPos+""+yPos);
                }
            }
        }
    }

    public int getxPos() {
        return xPos;
    }


    public int getyPos() {
        return yPos;
    }

    @Override
    public void run() {
        try{
            queue.put(xPos);
            Thread.sleep(1000);
            queue.put(yPos);
        }
        catch (InterruptedException e){
            e.printStackTrace();

        }
    }



}