零和交叉项目中的java空指针异常

我一直在做一个项目，这个项目是创造一个零和十字架的游戏。我已经为游戏打下了基础，现在我正在进一步发展它。但是，当我运行程序并选择AI进行第一步操作时，我在这一行返回了一个Java空指针异常：

if(Game.Board[0][0].getText().equals(Game.Board[1][1].getText()) && Game.Board[0][0].getText().equals(Game.PlayerMark))

游戏板[a][b]由3x3个按钮组成。PlayerMark是一个可以包含“X”或“O”的字符串

如何解决这个问题

在调用AI方法的地方：

    public void StartGame()
    {
         SideAssigner();
         State = true;

         if ( AIGame == true && FirstTurn ==true)
         {
             Computer.AI();

         }

         while ( State = true )
         {

             WinValidator();

         }

    }

控制台框中的消息：

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
    at Computer.AI(Computer.java:19)
    at Game.StartGame(Game.java:179)
    at Game$10.actionPerformed(Game.java:739)
    at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
    at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
    at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
    at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
    at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
    at java.awt.Component.processMouseEvent(Unknown Source)
    at javax.swing.JComponent.processMouseEvent(Unknown Source)
    at java.awt.Component.processEvent(Unknown Source)
    at java.awt.Container.processEvent(Unknown Source)
    at java.awt.Component.dispatchEventImpl(Unknown Source)
    at java.awt.Container.dispatchEventImpl(Unknown Source)
    at java.awt.Component.dispatchEvent(Unknown Source)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
    at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
    at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
    at java.awt.Container.dispatchEventImpl(Unknown Source)
    at java.awt.Window.dispatchEventImpl(Unknown Source)
    at java.awt.Component.dispatchEvent(Unknown Source)
    at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
    at java.awt.EventQueue.access$400(Unknown Source)
    at java.awt.EventQueue$3.run(Unknown Source)
    at java.awt.EventQueue$3.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
    at java.awt.EventQueue$4.run(Unknown Source)
    at java.awt.EventQueue$4.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
    at java.awt.EventQueue.dispatchEvent(Unknown Source)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.run(Unknown Sour

更新： 下面是如何确定每个JBUtton属性的示例：

        Button1.setText("");
        Button1.setEnabled(false);
        Button1.addActionListener(new ActionListener()
        {
            public void actionPerformed(ActionEvent e)
            {
                if ( State == true && playerO == true && PlayerGame == true )
                {
                    isEmpty = false;
                    Button1.setText("O");
                    // WinValidator
                    // TurnChecker ??
                }

                else if ( State == true && playerX == true && PlayerGame == true )
                {
                    isEmpty = false;
                    Button1.setText("X");
                    // WinValidator
                    // TurnChecker
                }

                else if ( State == true && computerO == true && AIGame == true)
                {
                    isEmpty = false;
                    // Call Computer Class
                    // WinValidator
                    // TurnChecker
                }

                else if ( State == true && computerX == true && AIGame == true)
                {
                    isEmpty = false;
                    // Call Computer Class
                    // WinValidator
                    // TurnChecker
                }

            }

        });

AI方法（它的片段，否则将太多而无法显示）：

公共静态无效AI（） {

---

for（int i=0；i以下是如何解决
NullPointerException
。您应该自己学习如何解决这些问题，因为您会遇到很多问题：

查看堆栈跟踪：

at Computer.AI(Computer.java:19)
at Game.StartGame(Game.java:179)

在跟踪的顶部找到该行：

if(Game.Board[0][0].getText().equals(Game.Board[1][1].getText()) && Game.Board[0][0].getText().equals(Game.PlayerMark))

如果看不到错误，请将行拆分为较小的语句：

tmp = Game.Board[0];
tmp2 = tmp1[0];
tmp3 = Game.Board[1];
tmp4 = tmp3[1];

等等，等等-我不确定是什么类型，但你会知道的

再次运行它，看看它落在哪里。行号现在将准确地告诉您哪个语句失败了。该语句中的引用必须为null

如果您不知道为什么引用为null，请按照逻辑返回并重复上面的更改

您还可以学习在Eclipse等IDE中使用调试器。
Game.Board[0][0]或Game.Board[1][1]是空的。如何解决它，我不知道，我想我们需要更多的源代码。@RobNeal编辑您的问题，不要将其作为注释发布，甚至更糟糕的是作为答案发布。发布您的AI方法以尽量避免使用大写名调用变量/实例（
StartGame
，
MadeMove
等）.虽然有效，但它违反惯例，使阅读变得困难。
tmp = Game.Board[0];
tmp2 = tmp1[0];
tmp3 = Game.Board[1];
tmp4 = tmp3[1];