Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at javax.swing.CellRendererPane.addImpl(CellRendererPane.java:85)
at java.awt.Container.add(Container.java:365)
at javax.swing.plaf.basic.BasicListUI.updateLayoutState(BasicListUI.java:1350)
at javax.swing.plaf.basic.BasicListUI.maybeUpdateLayoutState(BasicListUI.java:1299)
at javax.swing.plaf.basic.BasicListUI.getPreferredSize(BasicListUI.java:566)
at javax.swing.JComponent.getPreferredSize(JComponent.java:1632)
at javax.swing.ScrollPaneLayout.layoutContainer(ScrollPaneLayout.java:769)
at java.awt.Container.layout(Container.java:1421)
at java.awt.Container.doLayout(Container.java:1410)
at java.awt.Container.validateTree(Container.java:1507)
at java.awt.Container.validateTree(Container.java:1513)
at java.awt.Container.validateTree(Container.java:1513)
at java.awt.Container.validateTree(Container.java:1513)
at java.awt.Container.validateTree(Container.java:1513)
at java.awt.Container.validate(Container.java:1480)
at java.awt.Window.dispatchEventImpl(Window.java:2473)
at java.awt.Component.dispatchEvent(Component.java:4413)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)

at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)

经验：运行报错，从console控制台来看85行出错，传入了空值(NULL),所以返回源代码85行debug看值就行