Run SwingSet in ja locale. Go to Plain Text panel, click in large text area. Use input method to enter Japanese text. After you commit, the system indefinitely throws StringIndexOutOfBoundsExceptions.

see
http://javaweb.eng/~norbert/japanese/index.html
on how to use Japanese input methods.

Here's the exception info:
java.lang.StringIndexOutOfBoundsException: String index out of range: -77
        at java.lang.String.charAt(String.java:392)
        at sun.io.ByteToCharEUC_JP.getUnicode(ByteToCharEUC_JP.java:72)
        at sun.io.ByteToCharEUC_JP.convert(ByteToCharEUC_JP.java:150)
        at java.lang.String.<init>(String.java:262)
        at java.lang.String.<init>(String.java:343)
        at java.awt.Font.getGlyphSet(Font.java:1323)
        at java.awt.Font.getGlyphSet(Font.java:1165)
        at java.awt.Font.getGlyphSet(Font.java:1352)
        at sun.java2d.SunGraphics2D.drawString(SunGraphics2D.java:724)
        at sun.java2d.SunGraphics2D.drawString(SunGraphics2D.java:730)
        at java.awt.swing.SwingGraphics.drawString(SwingGraphics.java:266)
        at java.awt.Graphics.drawChars(Graphics.java:786)
        at java.awt.swing.text.Utilities.drawTabbedText(Utilities.java:69)
        at java.awt.swing.text.PlainView.drawUnselectedText(PlainView.java:146)
        at java.awt.swing.text.PlainView.drawLine(PlainView.java:106)
        at java.awt.swing.text.PlainView.paint(PlainView.java:270)
        at java.awt.swing.text.DefaultTextUI$RootView.paint(DefaultTextUI.java:741)
        at java.awt.swing.text.DefaultTextUI.paintSafely(DefaultTextUI.java:335)
        at java.awt.swing.text.DefaultTextUI$SafePainter.run(DefaultTextUI.java:999)
        at java.awt.swing.text.AbstractDocument.render(AbstractDocument.java:244)
        at java.awt.swing.text.DefaultTextUI.paint(DefaultTextUI.java:442)
        at java.awt.swing.plaf.ComponentUI.update(ComponentUI.java:47)
        at java.awt.swing.JComponent.paintComponent(JComponent.java:371)
        at java.awt.swing.JComponent.paint(JComponent.java:576)
        at java.awt.swing.JComponent.paintChildren(JComponent.java:431)
        at java.awt.swing.JComponent.paint(JComponent.java:579)
        at java.awt.swing.JViewport.paint(JViewport.java:266)
        at java.awt.swing.JComponent.paintWithBuffer(JComponent.java:3074)
        at java.awt.swing.JComponent._paintImmediately(JComponent.java:3037)
        at java.awt.swing.JComponent.paintImmediately(JComponent.java:2952)
        at java.awt.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:292)
        at java.awt.swing.RepaintManager.repaintDirtyRegions(RepaintManager.java:224)
        at java.awt.swing.RepaintManager$RepaintListener.actionPerformed(RepaintManager.java:452)
        at java.awt.swing.Timer.fireActionPerformed(Timer.java:124)
        at java.awt.swing.Timer$DummyComponent.processEvent(Timer.java:309)
        at java.awt.Component.dispatchEventImpl(Component.java:1917)
        at java.awt.Component.dispatchEvent(Component.java:1827)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:160)