[dongyijun123]

学习的过程中，有的时候用着用着，突然命令栏出现了这个东西，并且不停的循环，不知道是怎么回事，请高手指点。下面就是命令栏出现的循环的代码。
谢谢。
java.lang.IllegalArgumentException: Invalid substring range at java.text.AttributedString$AttributedStringIterator.(Unknown Source) at java.text.AttributedString.getIterator(Unknown Source) at javax.swing.text.Utilities.drawComposedText(Unknown Source) at javax.swing.text.PlainView.drawElement(Unknown Source) at javax.swing.text.PlainView.drawLine(Unknown Source) at com.mathworks.mde.cmdwin.CmdWinSyntaxUI$SyntaxPlainView.drawLine(CmdWinSyntaxUI.java:509) at javax.swing.text.PlainView.paint(Unknown Source) at javax.swing.plaf.basic.BasicTextUI$RootView.paint(Unknown Source) at javax.swing.plaf.basic.BasicTextUI.paintSafely(Unknown Source) at javax.swing.plaf.basic.BasicTextUI.paint(Unknown Source) at javax.swing.plaf.basic.BasicTextUI.update(Unknown Source) at javax.swing.JComponent.paintComponent(Unknown Source) at javax.swing.JComponent.paint(Unknown Source) at javax.swing.JComponent.paintChildren(Unknown Source) at javax.swing.JComponent.paint(Unknown Source) at javax.swing.JViewport.paint(Unknown Source) at javax.swing.JComponent.paintChildren(Unknown Source) at javax.swing.JComponent.paint(Unknown Source) at javax.swing.JComponent._paintImmediately(Unknown Source) at javax.swing.JComponent.paintImmediately(Unknown Source) at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source) at javax.swing.SystemEventQueueUtilities$ComponentWorkRequest.run(Unknown Source) at java.awt.event.InvocationEvent.dispatch(Unknown Source) at java.awt.EventQueue.dispatchEvent(Unknown Source) at java.awt.EventDispatchThread.pumpOneEventForHierarchy(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 Source)