向伟大的stackoverflow致敬。我最近一直在用java编程一个小的2D游戏，我想把它导出到一个applet中，可以在网页上运行。我这样做了，代码在作为applet和作为应用程序运行时都运行良好。但是，每当我将代码作为applet运行时，就会显示小的默认applet窗口，然后显示另一个具有正确大小的显示内容的窗口。我想这就是它不能在我的网页上正常显示的原因。我假设它正在显示第一个窗口的内容，即空窗口。我想知道我如何才能使它只显示一个窗口。我使用画布来显示我的窗口。我会上传任何代码要求。提前感谢!
- 链接到嵌入applet的applet PHP。
- 链接到applet存档。
Java Plug-in 10.5.1.255
Using JRE version 1.7.0_11-b21 Java HotSpot(TM) Client VM
User home directory = C:'Users'Andrew
----------------------------------------------------
c: clear console window
..
0-5: set trace level to <n>
----------------------------------------------------
Attempting to start init...
-INIT METHOD STARTED-
Preferred size set to java.awt.Dimension[width=852,height=480]
Initialized JFrame with size java.awt.Dimension[width=852,height=480]
Initialized screen (284x160)
Initialized keyboard
Added key listener
Resizeable set to false
Title set
Game component added to screen
Frame packed
Exception in thread "AWT-EventQueue-3" java.lang.NullPointerException
at sun.awt.SunToolkit.createImage(Unknown Source)
at com.sun.deploy.uitoolkit.impl.awt.AWTErrorPanel.getErrorImage(Unknown Source)
at com.sun.deploy.uitoolkit.impl.awt.AWTErrorPanel.paintComponent(Unknown Source)
at javax.swing.JComponent.paint(Unknown Source)
at javax.swing.JComponent.paintToOffscreen(Unknown Source)
at javax.swing.RepaintManager$PaintManager.paintDoubleBuffered(Unknown Source)
at javax.swing.RepaintManager$PaintManager.paint(Unknown Source)
at javax.swing.RepaintManager.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.RepaintManager.paintDirtyRegions(Unknown Source)
at javax.swing.RepaintManager.prePaintDirtyRegions(Unknown Source)
at javax.swing.RepaintManager.access$700(Unknown Source)
at javax.swing.RepaintManager$ProcessingRunnable.run(Unknown Source)
at java.awt.event.InvocationEvent.dispatch(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$200(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$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)
即没有小程序，就没有窗口。从控制台输出到跟踪级别5。
更新新结果:// ..
Frame packed
java.security.AccessControlException: access denied ("java.lang.RuntimePermission" "exitVM.0")
at java.security.AccessControlContext.checkPermission(Unknown Source)
at java.security.AccessController.checkPermission(Unknown Source)
代码(缺少SSCCE，我们只能猜测)是否在任何时候调用…
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
?
如果是，修改为:
// See http://stackoverflow.com/a/7143398/418556 for demo.
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
后者在沙箱applet中是允许的，而EXIT_ON_CLOSE即使在可信applet中也是不允许的。