I am getting a NullPointerException with JOptionPane on Linux with OpenJDK 1.6.0.22. I alert the user that a certain number of items must be selected. The thread is running on the Event Dispatch Thread.
JOptionPane.showMessageDialog(this, "At least one entity must be selected.",
"Selection Error", JOptionPane.ERROR_MESSAGE);
java.lang.NullPointerException
at sun.awt.X11.XWindowPeer.restoreTransientFor(XWindowPeer.java:1681)
at sun.awt.X11.XWindowPeer.removeFromTransientFors(XWindowPeer.java:1747)
at sun.awt.X11.XWindowPeer.setModalBlocked(XWindowPeer.java:1469)
at sun.awt.X11.XWindowPeer.setModalBlocked(XWindowPeer.java:1440)
at java.awt.Window.setModalBlocked(Window.java:1359)
at java.awt.Dialog.unblockWindow(Dialog.java:1597)
at java.awt.Dialog.modalHide(Dialog.java:1483)
at java.awt.Dialog.hideAndDisposePreHandler(Dialog.java:1215)
at java.awt.Dialog.hide(Dialog.java:1255)
at java.awt.Component.show(Component.java:1553)
at java.awt.Component.setVisible(Component.java:1503)
at java.awt.Window.setVisible(Window.java:881)
at java.awt.Dialog.setVisible(Dialog.java:1011)
at javax.swing.JOptionPane$3.propertyChange(JOptionPane.java:1021)
at java.beans.PropertyChangeSupport.fire(PropertyChangeSupport.java:298)
at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:291)
at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:229)
at java.awt.Component.firePropertyChange(Component.java:8148)
at javax.swing.JOptionPane.setValue(JOptionPane.java:1964)
at javax.swing.plaf.basic.BasicOptionPaneUI$ButtonActionListener.actionPerformed(BasicOptionPaneUI.java:1201)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2012)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2335)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:404)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:253)
at java.awt.Component.processMouseEvent(Component.java:6268)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3267)
at java.awt.Component.processEvent(Component.java:6033)
at java.awt.Container.processEvent(Container.java:2045)
at java.awt.Component.dispatchEventImpl(Component.java:4629)
at java.awt.Container.dispatchEventImpl(Container.java:2103)
at java.awt.Component.dispatchEvent(Component.java:4455)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4633)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4297)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4227)
at java.awt.Container.dispatchEventImpl(Container.java:2089)
at java.awt.Window.dispatchEventImpl(Window.java:2517)
at java.awt.Component.dispatchEvent(Component.java:4455)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:649)
at java.awt.EventQueue.access$000(EventQueue.java:96)
at java.awt.EventQueue$1.run(EventQueue.java:608)
at java.awt.EventQueue$1.run(EventQueue.java:606)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:105)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:116)
at java.awt.EventQueue$2.run(EventQueue.java:622)
at java.awt.EventQueue$2.run(EventQueue.java:620)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:105)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:619)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:275)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:200)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:194)
at java.awt.Dialog$1.run(Dialog.java:1072)
at java.awt.Dialog$3.run(Dialog.java:1126)
at java.security.AccessController.doPrivileged(Native Method)
at java.awt.Dialog.show(Dialog.java:1124)
at javax.swing.JOptionPane.showOptionDialog(JOptionPane.java:871)
at javax.swing.JOptionPane.showMessageDialog(JOptionPane.java:668)
at javax.swing.JOptionPane.showMessageDialog(JOptionPane.java:639)
at com.walterjwhite.ui.api.renderer.entity.MultipleEntitySelectorRenderer.isSingleRowSelected(MultipleEntitySelectorRenderer.java:191)
at com.walterjwhite.ui.api.renderer.entity.MultipleEntitySelectorRenderer.edit(MultipleEntitySelectorRenderer.java:151)
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:616)
at com.walterjwhite.ui.api.renderer.callback.ButtonCallbackHandler$1.actionPerformed(ButtonCallbackHandler.java:99)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2012)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2335)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:404)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:253)
at java.awt.Component.processMouseEvent(Component.java:6268)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3267)
at java.awt.Component.processEvent(Component.java:6033)
at java.awt.Container.processEvent(Container.java:2045)
at java.awt.Component.dispatchEventImpl(Component.java:4629)
at java.awt.Container.dispatchEventImpl(Container.java:2103)
at java.awt.Component.dispatchEvent(Component.java:4455)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4633)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4297)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4227)
at java.awt.Container.dispatchEventImpl(Container.java:2089)
at java.awt.Window.dispatchEventImpl(Window.java:2517)
at java.awt.Component.dispatchEvent(Component.java:4455)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:649)
at java.awt.EventQueue.access$000(EventQueue.java:96)
at java.awt.EventQueue$1.run(EventQueue.java:608)
at java.awt.EventQueue$1.run(EventQueue.java:606)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:105)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:116)
at java.awt.EventQueue$2.run(EventQueue.java:622)
at java.awt.EventQueue$2.run(EventQueue.java:620)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:105)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:619)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:275)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:200)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:190)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:185)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:177)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:138)
Still seem like a JVM bug. I would try to upgrade your JDK version version 7 where the bug seems fixed.
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