Java Game - ClassCastException - java

I am developing a simple java game and my scrollbar is raising an exception.
The scrollbar is supposed to be a "gameslider".
Exception in thread "Thread-3" java.lang.ClassCastException: sun.java2d.NullSurfaceData cannot be cast to sun.java2d.d3d.D3DSurfaceData
at sun.java2d.d3d.D3DRenderer.copyArea(Unknown Source)
at sun.java2d.d3d.D3DSurfaceData.copyArea(Unknown Source)
at sun.java2d.SunGraphics2D.doCopyArea(Unknown Source)
at sun.java2d.SunGraphics2D.copyArea(Unknown Source)
at javax.swing.BufferStrategyPaintManager.copyArea(Unknown Source)
at javax.swing.RepaintManager.copyArea(Unknown Source)
at javax.swing.JViewport.blitDoubleBuffered(Unknown Source)
at javax.swing.JViewport.windowBlitPaint(Unknown Source)
at javax.swing.JViewport.setViewPosition(Unknown Source)
at javax.swing.plaf.basic.BasicScrollPaneUI$Handler.hsbStateChanged(Unknown Source)
at javax.swing.plaf.basic.BasicScrollPaneUI$Handler.stateChanged(Unknown Source)
at javax.swing.DefaultBoundedRangeModel.fireStateChanged(Unknown Source)
at javax.swing.DefaultBoundedRangeModel.setRangeProperties(Unknown Source)
at javax.swing.DefaultBoundedRangeModel.setValue(Unknown Source)
at javax.swing.JScrollBar.setValue(Unknown Source)
at GameEnvironment.GamePanel.gameUpdate(GamePanel.java:171)
at GameEnvironment.GamePanel.run(GamePanel.java:73)
at java.lang.Thread.run(Unknown Source)
Code Line is following:
if (reachedMiddle)
scrollPane.getHorizontalScrollBar().setValue(player.getX() - (widthHorizontalScrollBar / 2));
The exception will be raised more or less randomly. I didnt figured it out so far.

I would make sure this code is run on the GUI Event Thread. If you call the Swing components on other threads you can get strange, randonm errors.
Have a look at using SwingUtilities.invokeLater(Runnable) to perform the tasks where the Swing components are updated.

Related

Stack overflow error encountered in AnyLogic

My model executed for the first 800 seconds after which I encounter the following error. Is there a way by which I can increase the stack size in AnyLogic? Is there any other approach I could use to counter the same?
`Exception during discrete event execution:
StackOverflowError
java.lang.StackOverflowError
at com.anylogic.engine.Agent.e(Unknown Source)
at com.anylogic.engine.Agent.h(Unknown Source)
at com.anylogic.engine.Agent.ext(Unknown Source)
at com.anylogic.libraries.processmodeling.OutPort.b(Unknown Source)
at com.anylogic.libraries.processmodeling.OutputBlock.forwardReadyEntityNotification(Unknown Source)
at com.anylogic.libraries.processmodeling.InputBlock$1.a(Unknown Source)
at com.anylogic.libraries.processmodeling.OutPort.a(Unknown Source)
at com.anylogic.libraries.processmodeling.OutPort.b(Unknown Source)
at com.anylogic.libraries.processmodeling.OutputBlock.forwardReadyEntityNotification(Unknown
Source)
at com.anylogic.libraries.processmodeling.InputBlock$1.a(Unknown Source)
at com.anylogic.libraries.processmodeling.OutPort.a(Unknown Source)
at com.anylogic.libraries.processmodeling.OutPort.b(Unknown Source)
at com.anylogic.libraries.processmodeling.OutputBlock.forwardReadyEntityNotification(Unknown
Source)`
I believe that you are using the free trial /(PLE) version of the AnyLogic software as the stack size is limited . The problem can be resolved by downsizing you model in terms of decreasing the number of agents or purchasing the full version here. https://www.anylogic.com/purchase/

Exception in "JavaFX Application Thread" when using JavaFX control

I am initializing a generic JavaFX 8 ComboBox with Enum values as follows:
ObservableList<MyEnumClass> myValues = FXCollections
.observableArrayList(MyEnumClass.FIRST_ENUM,
MyEnumClass.SECOND_ENUM, MyEnumClass.THIRD_ENUM);
myEnumComboBox = new ComboBox<MyEnumClass>(myValues);
A test application shows the ComboBox with the Enum values as expected and selecting other values also works fine. But one thing puzzels me: Even though I can not observe any apparent malfunction, my Eclipse console nevertheless notifies me about an exception in thread "JavaFX Application Thread" whenever I select a new value from the ComboBox's menu. The exception seems to be related to the native JavaFX code that hides the ComboBox's popup control:
Exception in thread "JavaFX Application Thread" java.lang.IllegalArgumentException: null source
at java.util.EventObject.<init>(Unknown Source)
at java.awt.AWTEvent.<init>(Unknown Source)
at sun.awt.UngrabEvent.<init>(Unknown Source)
at javafx.embed.swing.SwingNode$10.handle(Unknown Source)
[9 lines omitted]
at com.sun.javafx.event.EventUtil.fireEvent(Unknown Source)
at javafx.event.Event.fireEvent(Unknown Source)
at com.sun.javafx.stage.WindowPeerListener.focusUngrab(Unknown Source)
[4 lines omitted]
at com.sun.glass.ui.Window.handleWindowEvent(Unknown Source)
at com.sun.glass.ui.Window.notifyFocusUngrab(Unknown Source)
at com.sun.glass.ui.win.WinWindow._ungrabFocus(Native Method)
at com.sun.glass.ui.Window.ungrabFocus(Unknown Source)
at com.sun.javafx.tk.quantum.WindowStage.ungrabFocus(Unknown Source)
at javafx.stage.Window.decreaseFocusGrabCounter(Unknown Source)
at javafx.stage.PopupWindow.handleAutohideActivation(Unknown Source)
at javafx.stage.PopupWindow.impl_visibleChanged(Unknown Source)
at javafx.stage.Window$9.invalidated(Unknown Source)
at javafx.beans.property.BooleanPropertyBase.markInvalid(Unknown Source)
at javafx.beans.property.BooleanPropertyBase.set(Unknown Source)
at javafx.stage.Window.setShowing(Unknown Source)
at javafx.stage.Window.hide(Unknown Source)
at javafx.stage.PopupWindow.hide(Unknown Source)
at com.sun.javafx.scene.control.skin.ComboBoxPopupControl.hide(Unknown Source)
[44 lines omitted]
at java.lang.Thread.run(Unknown Source)
Can somebody explain what exactly is happening here and what I can or should do about it?
EDIT - The exception was caused by a leftover SwingNode from some earlier experiment on the same Pane as the ComboBox. Deleting the SwingNode made the exception vanish.

"Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException". I have no clue what I'm doing wrong

I am making a calculator for an AP Computer Science Final. I built the GUI in Eclipse using Jigloo, and I quickly tried to learn about Action Listeners so you can hit the buttons to make numbers appear. The problems started occurring when I started enter the actual code to make calculations. I keep getting the following error:
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at NewJFrame.<init>(NewJFrame.java:82)
at NewJFrame$1.run(NewJFrame.java:73)
at java.awt.event.InvocationEvent.dispatch(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$000(Unknown Source)
at java.awt.EventQueue$1.run(Unknown Source)
at java.awt.EventQueue$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(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)
I'm pretty new to Java, and I've never attempted a project like this before. I would love if you guys can help me fix this problem. Here is a link to my actual code, it won't fit in the code box for some reason: Link to code
You button variables aren't assigned until you call initGUI(), which is at the bottom of your constructor. So, when you do this:
jButton3.addActionListener(new ListenToOne());
... Java sees this:
null.addActionListener(new ListenToOne());
... which is obviously a problem.

Handle Applet throwing java.lang.ExceptionInInitializerError preventing it from running

We are developing java applet and embedding it in our web pages. When the applet is loaded via HTML APPLET tags, the browser/JVM prompts the user to allow it to run. When we hit cancel, the java console indicates the following exception:
java.lang.RuntimeException: java.lang.ExceptionInInitializerError
at sun.plugin2.applet.Plugin2Manager.createApplet(Unknown Source)
at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.ExceptionInInitializerError
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at java.lang.Class.newInstance0(Unknown Source)
at java.lang.Class.newInstance(Unknown Source)
at sun.plugin2.applet.Plugin2Manager$12.run(Unknown Source)
at java.awt.event.InvocationEvent.dispatch(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$000(Unknown Source)
at java.awt.EventQueue$1.run(Unknown Source)
at java.awt.EventQueue$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(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)
Caused by: java.security.AccessControlException: access denied (java.lang.RuntimePermission getenv.TEMP)
at java.security.AccessControlContext.checkPermission(Unknown Source)
at java.security.AccessController.checkPermission(Unknown Source)
at java.lang.SecurityManager.checkPermission(Unknown Source)
at java.lang.System.getenv(Unknown Source)
at downLoadApp.<clinit>(downLoadApp.java:15)
... 21 more
Exception: java.lang.RuntimeException: java.lang.ExceptionInInitializerError
Now, I realize it's most likely because the class java tried to load was prevented from loading, and therefore the exception is thrown, but how do we gracefully handle this situation in the browser? I'd like to detect that the applet was denied and post a reasonable response to the condition, but I'm unaware of how to catch this exception since it appears to have been thrown by the JVM in reaction to not getting the jar file to load rather than code written in it...
Ideas?
Thanks!
You can catch the access control exception by putting the call to System.getenv in downLoadApp.java line 15 in a try-catch statement. That is, instead of this:
static String tmp = System.getenv("TEMP");
you should have:
static String tmp;
static {
try {
tmp = System.getenv("TEMP");
} catch (java.security.AccessControlException ace) {
// tmp is not set, maybe use some default value?
}
}
Do you call System.getenv("TEMP") somewhere in the static context of the downLoadApp class? Most probably this is in the initializer of a static field, but it could be in a static code block.
This is the place where it fails (a java.security.AccessControlException is thrown). The rest of the stack trace are errors following from that. You need to catch this exception to detect that you don't have the appropriate permissions.
As you can't catch exceptions of static field initializers, you need to move the call to getenv into a method or a static code block.
I don't think that you can catch this exception as this is thrown by JVM while loading applet.

What is this thread/paint exception about?

I'm playing with things I don't really understand at the moment for a JAVA project on a Robot exploring an unknown territory (a grid of valid positions and blocked positions). Anyway, I tried to improve the basic GUI we were given as an example of how to proceed, it had been done with a text field and various unicode characters to represent the map and the robot. I tried to do it by overriding the paint method and drawing coloured rectangles to the screen to represent the map. When the program starts I'm presented with the runtime exception below but the window loads up (although for some reason the JButtons at the top are all invisible until i roll my mouse over them) and functions fine from then on.
I've got this far by trial and error and playing with examples I've found online but I guess there's something fundamental I haven't grasped here.
Thanks for any advice you can give me here.
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at Controller.paint(Controller.java:156)
at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source)
at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source)
at javax.swing.RepaintManager.seqPaintDirtyRegions(Unknown Source)
at javax.swing.SystemEventQueueUtilities$ComponentWorkRequest.run(Unknow
n Source)
at java.awt.event.InvocationEvent.dispatch(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at Controller.paint(Controller.java:156)
at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source)
at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source)
at javax.swing.RepaintManager.seqPaintDirtyRegions(Unknown Source)
at javax.swing.SystemEventQueueUtilities$ComponentWorkRequest.run(Unknow
n Source)
at java.awt.event.InvocationEvent.dispatch(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(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)
I suggest you start by reading the Swing tutorial. It contains a section that explains how painting is done. For one thing you should be overriding the paintComponent() method. From the above error it appears your code is in the paint() method.
To learn something you should start small, then when you have problems you can post a SSCCE showing the problem.

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