Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at org.pushingpixels.substance.internal.utils.SubstanceColorUtilities.getDefaultBackgroundColor(SubstanceColorUtilities.java:758)
at org.pushingpixels.substance.internal.utils.SubstanceColorUtilities.getBackgroundFillColor(SubstanceColorUtilities.java:661)
at org.pushingpixels.substance.internal.ui.SubstancePanelUI.__org__pushingpixels__substance__internal__ui__SubstancePanelUI__installDefaults(SubstancePanelUI.java:73)
at org.pushingpixels.substance.internal.ui.SubstancePanelUI.installDefaults(SubstancePanelUI.java)
at javax.swing.plaf.basic.BasicPanelUI.installUI(BasicPanelUI.java:56)
at org.pushingpixels.substance.internal.ui.SubstancePanelUI.__org__pushingpixels__substance__internal__ui__SubstancePanelUI__installUI(SubstancePanelUI.java)
at org.pushingpixels.substance.internal.ui.SubstancePanelUI.installUI(SubstancePanelUI.java)
at javax.swing.JComponent.setUI(JComponent.java:664)
at javax.swing.JPanel.setUI(JPanel.java:153)
at javax.swing.JPanel.updateUI(JPanel.java:126)
at javax.swing.JPanel.<init>(JPanel.java:86)
at javax.swing.JPanel.<init>(JPanel.java:109)
at javax.swing.JPanel.<init>(JPanel.java:117)
at javax.swing.JRootPane.createGlassPane(JRootPane.java:545)
at javax.swing.JRootPane.<init>(JRootPane.java:365)
at javax.swing.JFrame.createRootPane(JFrame.java:277)
at javax.swing.JFrame.frameInit(JFrame.java:258)
at javax.swing.JFrame.<init>(JFrame.java:225)
at Walkthrough.<init>(Walkthrough.java:7)
at Main1$1.run(Main1.java:17)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:251)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:733)
at java.awt.EventQueue.access$200(EventQueue.java:103)
at java.awt.EventQueue$3.run(EventQueue.java:694)
at java.awt.EventQueue$3.run(EventQueue.java:692)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:703)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)
我从http://insubstantial.github.io/insubstantial/substance/docs/getting-started.html创建了教程。 some1能告诉我问题出在哪里？我添加了所有库并创建了两个类：
Main代码如下所示在tuto Walkthrough 调试告诉异常在返回新ColorUIResource时创建。