好吧，伙计们，我遇到了一个新问题，我做了一个计时器，检查按钮是否每秒都符合某些要求，并且我知道这不是最好的方法，但我不会长时间使用这个程序所以我只是想让它发挥作用。
我遇到的问题是计时器给出了以下错误：
Exception in thread "Timer-0" java.lang.NullPointerException
at proyecto.Diseños$RemindTask.run(Diseños.java:3561)
at java.util.TimerThread.mainLoop(Timer.java:555)
at java.util.TimerThread.run(Timer.java:505)
第3561行是：
if(Boton61.getBackground() == Color.red && Boton51.getBackground() == Color.red && Boton41.getBackground() == Color.red && Boton31.getBackground() == Color.red
&& colores.colorjugador[0] == 1) System.out.println("El jugador ha ganado !");
完整的代码是：
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package proyecto;
import java.awt.Color;
import java.awt.Component;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JComponent;
import static proyecto.Proyecto.turnosjugador1;
import static proyecto.Proyecto.turnosjugador2;
import java.util.Timer;
import java.util.TimerTask;
/**
*
* @author Cristian
*
* */
public class Diseños extends JComponent implements ActionListener {
JButton Boton1, Boton2, Boton3, Boton4, Boton5, Boton6, Boton7;
JButton Boton11,Boton21,Boton31,Boton41,Boton51,Boton61;
JButton Boton12,Boton22,Boton32,Boton42,Boton52,Boton62;
JButton Boton13,Boton23,Boton33,Boton43,Boton53,Boton63;
JButton Boton14,Boton24,Boton34,Boton44,Boton54,Boton64;
JButton Boton15,Boton25,Boton35,Boton45,Boton55,Boton65;
JButton Boton16,Boton26,Boton36,Boton46,Boton56,Boton66;
JButton Boton17,Boton27,Boton37,Boton47,Boton57,Boton67;
public Diseños()
{
Timer timer;
timer = new Timer();
timer.schedule(new RemindTask(), 0, //initial delay
1 * 1000);
Boton1=new JButton("lol");
Boton1.setBounds(90, 410, 30, 30);
Boton1.setBackground(Color.black);
Component agregar1 = add(Boton1);
Boton1.addActionListener(this);
Boton2=new JButton("lol");
Boton2.setBounds(150, 410, 30, 30);
Boton2.setBackground(Color.black);
Component agregar2 = add(Boton2);
Boton2.addActionListener(this);
Boton3=new JButton("lol");
Boton3.setBounds(210, 410, 30, 30);
Boton3.setBackground(Color.black);
Component agregar3 = add(Boton3);
Boton3.addActionListener(this);
Boton4=new JButton("lol");
Boton4.setBounds(270, 410, 30, 30);
Boton4.setBackground(Color.black);
Component agregar4 = add(Boton4);
Boton4.addActionListener(this);
Boton5=new JButton("lol");
Boton5.setBounds(330, 410, 30, 30);
Boton5.setBackground(Color.black);
Component agregar5 = add(Boton5);
Boton5.addActionListener(this);
Boton6=new JButton("lol");
Boton6.setBounds(390, 410, 30, 30);
Boton6.setBackground(Color.black);
Component agregar6 = add(Boton6);
Boton6.addActionListener(this);
Boton7=new JButton("lol");
Boton7.setBounds(450, 410, 30, 30);
Boton7.setBackground(Color.black);
Component agregar7 = add(Boton7);
Boton7.addActionListener(this);
Boton11=new JButton("");
Boton11.setBounds(85, 10, 40, 60);
Boton11.setBackground(Color.white);
Component agregar11 = add(Boton11);
Boton11.addActionListener(this);
Boton21=new JButton("");
Boton21.setBounds(85, 70, 40, 60);
Boton21.setBackground(Color.white);
Component agregar21 = add(Boton21);
Boton21.addActionListener(this);
Boton31=new JButton("");
Boton31.setBounds(85, 130, 40, 60);
Boton31.setBackground(Color.white);
Component agregar31 = add(Boton31);
Boton31.addActionListener(this);
Boton41=new JButton("");
Boton41.setBounds(85, 190, 40, 60);
Boton41.setBackground(Color.white);
Component agregar41 = add(Boton41);
Boton41.addActionListener(this);
Boton51=new JButton("");
Boton51.setBounds(85, 250, 40, 60);
Boton51.setBackground(Color.white);
Component agregar51 = add(Boton51);
Boton51.addActionListener(this);
Boton61=new JButton("");
Boton61.setBounds(85, 310, 40, 60);
Boton61.setBackground(Color.white);
Component agregar61 = add(Boton61);
Boton61.addActionListener(this);
Boton12=new JButton("");
Boton12.setBounds(145, 10, 40, 60);
Boton12.setBackground(Color.white);
Component agregar12 = add(Boton12);
Boton12.addActionListener(this);
Boton22=new JButton("");
Boton22.setBounds(145, 70, 40, 60);
Boton22.setBackground(Color.white);
Component agregar22 = add(Boton22);
Boton22.addActionListener(this);
Boton32=new JButton("");
Boton32.setBounds(145, 130, 40, 60);
Boton32.setBackground(Color.white);
Component agregar32 = add(Boton32);
Boton32.addActionListener(this);
Boton42=new JButton("");
Boton42.setBounds(145, 190, 40, 60);
Boton42.setBackground(Color.white);
Component agregar42 = add(Boton42);
Boton42.addActionListener(this);
Boton52=new JButton("");
Boton52.setBounds(145, 250, 40, 60);
Boton52.setBackground(Color.white);
Component agregar52 = add(Boton52);
Boton52.addActionListener(this);
Boton62=new JButton("");
Boton62.setBounds(145, 310, 40, 60);
Boton62.setBackground(Color.white);
Component agregar62 = add(Boton62);
Boton62.addActionListener(this);
Boton13=new JButton("");
Boton13.setBounds(205, 10, 40, 60);
Boton13.setBackground(Color.white);
Component agregar13 = add(Boton13);
Boton13.addActionListener(this);
Boton23=new JButton("");
Boton23.setBounds(205, 70, 40, 60);
Boton23.setBackground(Color.white);
Component agregar23 = add(Boton23);
Boton23.addActionListener(this);
Boton33=new JButton("");
Boton33.setBounds(205, 130, 40, 60);
Boton33.setBackground(Color.white);
Component agregar33 = add(Boton33);
Boton33.addActionListener(this);
Boton43=new JButton("");
Boton43.setBounds(205, 190, 40, 60);
Boton43.setBackground(Color.white);
Component agregar43 = add(Boton43);
Boton43.addActionListener(this);
Boton53=new JButton("");
Boton53.setBounds(205, 250, 40, 60);
Boton53.setBackground(Color.white);
Component agregar53 = add(Boton53);
Boton53.addActionListener(this);
Boton63=new JButton("");
Boton63.setBounds(205, 310, 40, 60);
Boton63.setBackground(Color.white);
Component agregar63 = add(Boton63);
Boton63.addActionListener(this);
Boton14=new JButton("");
Boton14.setBounds(265, 10, 40, 60);
Boton14.setBackground(Color.white);
Component agregar14 = add(Boton14);
Boton14.addActionListener(this);
Boton24=new JButton("");
Boton24.setBounds(265, 70, 40, 60);
Boton24.setBackground(Color.white);
Component agregar24 = add(Boton24);
Boton24.addActionListener(this);
Boton34=new JButton("");
Boton34.setBounds(265, 130, 40, 60);
Boton34.setBackground(Color.white);
Component agregar34 = add(Boton34);
Boton34.addActionListener(this);
Boton44=new JButton("");
Boton44.setBounds(265, 190, 40, 60);
Boton44.setBackground(Color.white);
Component agregar44 = add(Boton44);
Boton44.addActionListener(this);
Boton54=new JButton("");
Boton54.setBounds(265, 250, 40, 60);
Boton54.setBackground(Color.white);
Component agregar54 = add(Boton54);
Boton54.addActionListener(this);
Boton64=new JButton("");
Boton64.setBounds(265, 310, 40, 60);
Boton64.setBackground(Color.white);
Component agregar64 = add(Boton64);
Boton64.addActionListener(this);
Boton15=new JButton("");
Boton15.setBounds(325, 10, 40, 60);
Boton15.setBackground(Color.white);
Component agregar15 = add(Boton15);
Boton15.addActionListener(this);
Boton25=new JButton("");
Boton25.setBounds(325, 70, 40, 60);
Boton25.setBackground(Color.white);
Component agregar25 = add(Boton25);
Boton25.addActionListener(this);
Boton35=new JButton("");
Boton35.setBounds(325, 130, 40, 60);
Boton35.setBackground(Color.white);
Component agregar35 = add(Boton35);
Boton35.addActionListener(this);
Boton45=new JButton("");
Boton45.setBounds(325, 190, 40, 60);
Boton45.setBackground(Color.white);
Component agregar45 = add(Boton45);
Boton45.addActionListener(this);
Boton55=new JButton("");
Boton55.setBounds(325, 250, 40, 60);
Boton55.setBackground(Color.white);
Component agregar55 = add(Boton55);
Boton55.addActionListener(this);
Boton65=new JButton("");
Boton65.setBounds(325, 310, 40, 60);
Boton65.setBackground(Color.white);
Component agregar65 = add(Boton65);
Boton65.addActionListener(this);
Boton16=new JButton("");
Boton16.setBounds(385, 10, 40, 60);
Boton16.setBackground(Color.white);
Component agregar16 = add(Boton16);
Boton16.addActionListener(this);
Boton26=new JButton("");
Boton26.setBounds(385, 70, 40, 60);
Boton26.setBackground(Color.white);
Component agregar26 = add(Boton26);
Boton26.addActionListener(this);
Boton36=new JButton("");
Boton36.setBounds(385, 130, 40, 60);
Boton36.setBackground(Color.white);
Component agregar36 = add(Boton36);
Boton36.addActionListener(this);
Boton46=new JButton("");
Boton46.setBounds(385, 190, 40, 60);
Boton46.setBackground(Color.white);
Component agregar46 = add(Boton46);
Boton46.addActionListener(this);
Boton56=new JButton("");
Boton56.setBounds(385, 250, 40, 60);
Boton56.setBackground(Color.white);
Component agregar56 = add(Boton56);
Boton56.addActionListener(this);
Boton66=new JButton("");
Boton66.setBounds(385, 310, 40, 60);
Boton66.setBackground(Color.white);
Component agregar66 = add(Boton66);
Boton66.addActionListener(this);
Boton17=new JButton("");
Boton17.setBounds(445, 10, 40, 60);
Boton17.setBackground(Color.white);
Component agregar17 = add(Boton17);
Boton17.addActionListener(this);
Boton27=new JButton("");
Boton27.setBounds(445, 70, 40, 60);
Boton27.setBackground(Color.white);
Component agregar27 = add(Boton27);
Boton27.addActionListener(this);
Boton37=new JButton("");
Boton37.setBounds(445, 130, 40, 60);
Boton37.setBackground(Color.white);
Component agregar37 = add(Boton37);
Boton37.addActionListener(this);
Boton47=new JButton("");
Boton47.setBounds(445, 190, 40, 60);
Boton47.setBackground(Color.white);
Component agregar47 = add(Boton47);
Boton47.addActionListener(this);
Boton57=new JButton("");
Boton57.setBounds(445, 250, 40, 60);
Boton57.setBackground(Color.white);
Component agregar57 = add(Boton57);
Boton57.addActionListener(this);
Boton67=new JButton("");
Boton67.setBounds(445, 310, 40, 60);
Boton67.setBackground(Color.white);
Component agregar67 = add(Boton67);
Boton67.addActionListener(this);
}
@Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawRect (570, 10, 300, 200);
g.setColor(Color.BLACK);
g.fillRect(570, 10, 300, 200);
g.drawRect (570, 250, 300, 200);
g.setColor(Color.BLACK);
g.fillRect(570, 250, 300, 200);
g.setColor(Color.WHITE);
Font oldFont=getFont();
Font fuente=new Font("Primer Jugador", Font.BOLD, 14);
g.setFont(fuente);
g.drawString("Primer Jugador", 580, 30);
Font titulo=new Font("Segundo Jugador", Font.BOLD, 14);
g.setFont(titulo);
g.drawString("Segundo Jugador", 580, 270);
g.drawString("[ " + Proyecto.primernombre + " ]", 580, 50);
g.drawString("[ " + Proyecto.segundonombre + " ]", 580, 290);
g.setColor(Color.CYAN);
g.fillRoundRect(10, 5, 550, 450, 50, 50);
g.drawString("Turno Numero : " + turnosjugador1, 580, 70);
g.drawString("Turno Numero : " + turnosjugador2, 580, 310);
}
}
class RemindTask extends TimerTask {
@Override
public void run() {
if(Boton61.getBackground() == Color.red && Boton51.getBackground() == Color.red && Boton41.getBackground() == Color.red && Boton31.getBackground() == Color.red
&& colores.colorjugador[0] == 1) System.out.println("El jugador ha ganado !");
//timer.cancel(); //Not necessary because we call System.exit
}
}
}
我知道很多行都浪费了不必要的空间，程序可以通过循环缩短，但我需要尽可能简单，以便其他学生理解它。
我只是想知道为什么计时器在计时器上使用IF时会给我这样的错误，非常感谢任何建议。
答案 0 :(得分：1)
在初始化课程时，计时器可能已执行...如果你看一下JavaDocs，delay参数是
延迟 - 在执行任务之前以毫秒为单位的延迟。
这意味着它可能几乎立即执行，这意味着您依赖的某些实例字段尚未初始化。
在处理Swing UI时，通常最好使用javax.swing.Timer，因为它在事件调度线程的上下文中调用ActionListener，从而降低了竞争条件的风险。
最好简单地将ActionListener附加到按钮上，并在点击时查看状态，但这只是我的意见