Nimbus：java.lang.ClassCastException: javax.swing.plaf.nimbus.DerivedColor$UIResource无法转换为javax.swing.Painter

Question

我正在使用Nimbus外观在我的Swing应用程序中。

有时，当显示对话框（使用dialog.setVisible(true)）时，Nimbus外观会抛出以下异常：

Caugth exception of type java.lang.ClassCastException with message javax.swing.plaf.nimbus.DerivedColor$UIResource cannot be cast to javax.swing.Painter 
java.lang.ClassCastException: javax.swing.plaf.nimbus.DerivedColor$UIResource cannot be cast to javax.swing.Painter
    at javax.swing.plaf.nimbus.NimbusStyle.getBackgroundPainter(NimbusStyle.java:708)
    at javax.swing.plaf.nimbus.SynthPainterImpl.paintBackground(SynthPainterImpl.java:99)
    at javax.swing.plaf.nimbus.SynthPainterImpl.paintPanelBackground(SynthPainterImpl.java:957)
    at javax.swing.plaf.synth.SynthPanelUI.update(SynthPanelUI.java:155)
    at javax.swing.JComponent.paintComponent(JComponent.java:778)
    at javax.swing.JComponent.paint(JComponent.java:1054)
    at javax.swing.JComponent.paintToOffscreen(JComponent.java:5221)
    at javax.swing.RepaintManager$PaintManager.paintDoubleBuffered(RepaintManager.java:1482)
    at javax.swing.RepaintManager$PaintManager.paint(RepaintManager.java:1413)
    at javax.swing.RepaintManager.paint(RepaintManager.java:1206)
    at javax.swing.JComponent._paintImmediately(JComponent.java:5169)
    at javax.swing.JComponent.paintImmediately(JComponent.java:4980)
    at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:770)
    at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:728)
    at javax.swing.RepaintManager.prePaintDirtyRegions(RepaintManager.java:677)
    at javax.swing.RepaintManager.access$700(RepaintManager.java:59)
    at javax.swing.RepaintManager$ProcessingRunnable.run(RepaintManager.java:1621)
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:251)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:721)
    at java.awt.EventQueue.access$200(EventQueue.java:103)
    at java.awt.EventQueue$3.run(EventQueue.java:682)
    at java.awt.EventQueue$3.run(EventQueue.java:680)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:691)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:244)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:163)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:155)
    at java.awt.WaitDispatchSupport$2.run(WaitDispatchSupport.java:182)
    at java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:221)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.awt.WaitDispatchSupport.enter(WaitDispatchSupport.java:219)
    at java.awt.Dialog.show(Dialog.java:1077)
    at java.awt.Component.show(Component.java:1651)
    at java.awt.Component.setVisible(Component.java:1603)
    at java.awt.Window.setVisible(Window.java:1014)
    at java.awt.Dialog.setVisible(Dialog.java:1003)
    at java_awt_Dialog$setVisible.call(Unknown Source)
    at org.openfidelia.views.core.impl.WorkbenchImpl$_showViewAsDialog_closure1.doCall(WorkbenchImpl.groovy:375)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at org.codehaus.groovy.runtime.callsite.PogoMetaMethodSite$PogoCachedMethodSite.invoke(PogoMetaMethodSite.java:226)
    at org.codehaus.groovy.runtime.callsite.PogoMetaMethodSite.callCurrent(PogoMetaMethodSite.java:52)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callCurrent(AbstractCallSite.java:141)
    at org.openfidelia.views.core.impl.WorkbenchImpl$_showViewAsDialog_closure1.doCall(WorkbenchImpl.groovy)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:90)
    at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:233)
    at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1047)
    at groovy.lang.ExpandoMetaClass.invokeMethod(ExpandoMetaClass.java:1110)
    at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:877)
    at groovy.lang.Closure.call(Closure.java:412)
    at groovy.lang.Closure.call(Closure.java:406)
    at groovy.lang.Closure.run(Closure.java:490)
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:241)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:721)
    at java.awt.EventQueue.access$200(EventQueue.java:103)
    at java.awt.EventQueue$3.run(EventQueue.java:682)
    at java.awt.EventQueue$3.run(EventQueue.java:680)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:691)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:244)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:163)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:155)
    at java.awt.WaitDispatchSupport$2.run(WaitDispatchSupport.java:182)
    at java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:221)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.awt.WaitDispatchSupport.enter(WaitDispatchSupport.java:219)
    at java.awt.Dialog.show(Dialog.java:1077)
    at java.awt.Component.show(Component.java:1651)
    at java.awt.Component.setVisible(Component.java:1603)
    at java.awt.Window.setVisible(Window.java:1014)
    at java.awt.Dialog.setVisible(Dialog.java:1003)
    at java_awt_Dialog$setVisible.call(Unknown Source)
    at org.openfidelia.views.core.impl.WorkbenchImpl$_showViewAsDialog_closure1.doCall(WorkbenchImpl.groovy:375)

我不知道这种情况何时发生，它很少发生，通常在显示对话框时出现。

我已经在Google上搜索过（http://netbeans.org/bugzilla/show_bug.cgi?id=212757），更多的人也遇到了这个问题，但似乎没有人知道这个问题的原因。

还有其他人遇到过这个问题吗？也许这是一个Nimbus的错误？

- Sergio Trapiello

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请从您的代码中返回，本机操作系统，JDK，JRE，只是出于我的好奇心... - mKorbel

不一定是Nimbus的错误：可能是某些应用程序/第三方代码意外地使用了错误的值类型设置UI属性，例如UIManager.put("Panel.backgroundPainter", UIManager.get("Panel.background"))。无论是谁造成的问题，这些错误很难追踪，最好的方法是a）尝试以某种方式使其可重现b）进行调试。 - kleopatra

Answer 1

我最近找到了解决这种重绘问题的方法，就是在触发UI更新并最终导致异常的应用程序代码点处转储当前线程：

LOGGER.debug("当前线程：" + Thread.currentThread());

如果打印出的线程不是Thread[AWT-EventQueue-0,6,main]（其中数字可以是任何值），那么您正在尝试在Swing事件分派线程之外执行UI更新，重绘问题几乎是不可避免的。

使用 SwingUtilities.invokeLater()或.invokeAndWait()可能会缓解此问题，但通常此问题将指向应用程序设计中的错误。在我的情况下，我（不必要地）设置了JTree的单元格渲染器作为更新树模型的一部分。

- Matthew Wise