向JAVA SWING组件高手求助

Question

一个局域网聊天程序的对话框模块出问题。
也没抛出异常代码在哪一行，郁闷滴很，这是抛出的全部异常。
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
        at javax.swing.plaf.basic.BasicTextUI$RootView.paint(Unknown Source)
        at javax.swing.plaf.basic.BasicTextUI.paintSafely(Unknown Source)
        at javax.swing.plaf.basic.BasicTextUI.paint(Unknown Source)
        at javax.swing.plaf.basic.BasicTextUI.update(Unknown Source)
        at javax.swing.JComponent.paintComponent(Unknown Source)
        at javax.swing.JComponent.paint(Unknown Source)
        at javax.swing.JComponent.paintChildren(Unknown Source)
        at javax.swing.JComponent.paint(Unknown Source)
        at javax.swing.JViewport.paint(Unknown Source)
        at javax.swing.JComponent.paintChildren(Unknown Source)
        at javax.swing.JComponent.paint(Unknown Source)
        at javax.swing.JComponent.paintToOffscreen(Unknown Source)
        at javax.swing.RepaintManager$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$000(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)我估摸着是不是问题出在这里：
public void appendReceiveText(String sendInfo, Color color) {
Style style = jTextPane1.addStyle("title", null);
StyleConstants.setForeground(style, color);
jTextPane1.setEditable(true);
jTextPane1.setCaretPosition(jTextPane1.getDocument().getLength());
jTextPane1.setCharacterAttributes(style, false);
jTextPane1.replaceSelection(sendInfo + "\n");
jTextPane1.setEditable(false);
}//不同用户的发言字体颜色设置为不同
JavaSwing异常聊天工具Color

Answer 1

DEBUG一下代码，看哪行出的异常，再判断是哪个变量导致了空指针

Answer 2

初始化操作以及数据类型不匹配都有可能
仔细看看自己代码哪里出问题了debug多用用就可以查到~

Answer 3

我看到这里有个null，会是它吗：
“Style style = jTextPane1.addStyle("title", null);”