Java键类型的问题

当我试着运行我的程序并按下一个键时，我总是遇到同样的错误

该错误表明问题出在keyTyped函数中，但我觉得这很好

你觉得怎么样？

代码：

错误：

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at RoofRunnerGame$GameKeyListener.keyTyped(RoofRunnerGame.java:106)
at java.awt.Component.processKeyEvent(Component.java:6303)
at java.awt.Component.processEvent(Component.java:6125)
at java.awt.Container.processEvent(Container.java:2085)
at java.awt.Window.processEvent(Window.java:1836)
at java.awt.Component.dispatchEventImpl(Component.java:4714)
at java.awt.Container.dispatchEventImpl(Container.java:2143)
at java.awt.Window.dispatchEventImpl(Window.java:2478)
at java.awt.Component.dispatchEvent(Component.java:4544)
at java.awt.KeyboardFocusManager.redispatchEvent(KeyboardFocusManager.java:1850)
at java.awt.DefaultKeyboardFocusManager.dispatchKeyEvent(DefaultKeyboardFocusManager.java:712)
at java.awt.DefaultKeyboardFocusManager.preDispatchKeyEvent(DefaultKeyboardFocusManager.java:990)
at java.awt.DefaultKeyboardFocusManager.typeAheadAssertions(DefaultKeyboardFocusManager.java:855)
at java.awt.DefaultKeyboardFocusManager.dispatchEvent(DefaultKeyboardFocusManager.java:676)
at java.awt.Component.dispatchEventImpl(Component.java:4586)
at java.awt.Container.dispatchEventImpl(Container.java:2143)
at java.awt.Window.dispatchEventImpl(Window.java:2478)
at java.awt.Component.dispatchEvent(Component.java:4544)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:635)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:296)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:211)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:196)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:188)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)

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我认为变量在第106行没有正确初始化。可能是计时器？

在队列中

timer.start();     // Add timer. Start game here

您确定计时器不是空的吗

timer.start();     // Add timer. Start game here