Question

该计划：

一个简单的模拟器，用于学习Java的基础知识。用户可以在提供的编辑器中输入他自己的代码，该编辑器将玩家移动到一个字段中。此代码在单独的线程中执行。除了当前这个问题，程序运行正常，这个错误突然出现，之前没有出现过。

问题：

出于某种原因，在随机时间间隔内，玩家会抛出下面看到的异常。玩家执行的操作无关紧要，因为这也会在执行无限重复单个动作的随机时间后显示出来。每次执行该字段上的任何操作时都会抛出此错误，这意味着控制台日志会一遍又一遍地填充相同的错误消息。

守则

这是用户代码的执行方式，CompileActionListener调用JavaCompiler：

method = CompileActionListener.getNewActor().getClass().getMethod("main");
method.invoke(CompileActionListener.getNewActor());

就我而言，其他代码不应该抛出所述执行（堆栈树不会暗示我自己的任何类）。由于这是一个NPE，应该很容易追溯，但由于缺乏对我的班级和随机时间间隔的引用，我无能为力。

堆栈跟踪

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at javax.swing.text.GlyphView.getBreakSpot(GlyphView.java:799)
at javax.swing.text.GlyphView.getBreakWeight(GlyphView.java:724)
at javax.swing.text.FlowView$LogicalView.getPreferredSpan(FlowView.java:733)
at javax.swing.text.FlowView.calculateMinorAxisRequirements(FlowView.java:233)
at javax.swing.text.ParagraphView.calculateMinorAxisRequirements(ParagraphView.java:717)
at javax.swing.text.BoxView.checkRequests(BoxView.java:935)
at javax.swing.text.BoxView.getMinimumSpan(BoxView.java:568)
at javax.swing.text.BoxView.calculateMinorAxisRequirements(BoxView.java:903)
at javax.swing.text.BoxView.checkRequests(BoxView.java:935)
at javax.swing.text.BoxView.setSpanOnAxis(BoxView.java:343)
at javax.swing.text.BoxView.layout(BoxView.java:708)
at javax.swing.text.BoxView.setSize(BoxView.java:397)
at javax.swing.plaf.basic.BasicTextUI$RootView.setSize(BasicTextUI.java:1722)
at javax.swing.plaf.basic.BasicTextUI.getPreferredSize(BasicTextUI.java:912)
at javax.swing.JComponent.getPreferredSize(JComponent.java:1659)
at javax.swing.JEditorPane.getPreferredSize(JEditorPane.java:1332)
at java.awt.BorderLayout.layoutContainer(BorderLayout.java:821)
at java.awt.Container.layout(Container.java:1508)
at java.awt.Container.doLayout(Container.java:1497)
at java.awt.Container.validateTree(Container.java:1693)
at java.awt.Container.validateTree(Container.java:1702)
at java.awt.Container.validateTree(Container.java:1702)
at java.awt.Container.validate(Container.java:1628)
at javax.swing.RepaintManager$3.run(RepaintManager.java:704)
at javax.swing.RepaintManager$3.run(RepaintManager.java:702)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)
at javax.swing.RepaintManager.validateInvalidComponents(RepaintManager.java:701)
at javax.swing.RepaintManager$ProcessingRunnable.run(RepaintManager.java:1719)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:744)
at java.awt.EventQueue.access$400(EventQueue.java:97)
at java.awt.EventQueue$3.run(EventQueue.java:697)
at java.awt.EventQueue$3.run(EventQueue.java:691)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:714)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)

谢谢你转发＆lt; 3

Answer 1

您可以使用功能强大的try / catch轻松解决问题。

在AWT-EventQueue-0中导致此NullPointerException的原因是什么？

1 个答案: