创建 JTextPane 导致 NullPointerException - OpenOffice Extension

Question

我目前正在开发 OpenOffice 的扩展。我正在使用 Java 1.6 和 OpenOffice SDK 4.1.2。

如果我尝试创建 javax.swing.JTextPane，我会在 JTextPane 的构造函数中得到 NullpointerException。

public class Dialog extends javax.JFrame {

private final JTextPane jTextPane;
private final JTable jTable;



    public Dialog()  {
         jTable = new JTable();
         jTextPane = new JTextPane();

    }
}

对话框在另一个线程中初始化：

public class DialogManager {
private static JournalDialog journalDialog;

public void showDialog() {




Thread startThread = new Thread(new Runnable() {


        @Override
        public void run() {

            SwingUtilities.invokeLater(new Runnable() {

                @Override
                public void run() {
                     dialog = new Dialog();
                     ...
                }
            }
        }
 }
}}

JTable 的创建工作正常，但在下一行我得到一个 Nullpointerexception

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at java.util.Hashtable.put(Unknown Source)
at javax.swing.JEditorPane.registerEditorKitForContentType(Unknown Source)
at javax.swing.JEditorPane.registerEditorKitForContentType(Unknown Source)
at javax.swing.JEditorPane.loadDefaultKitsIfNecessary(Unknown Source)
at javax.swing.JEditorPane.getKitTypeRegistry(Unknown Source)
at javax.swing.JEditorPane.getEditorKitClassNameForContentType(Unknown Source)
at javax.swing.JTextPane.<init>(Unknown Source)
at .gui.Dialog.<init>(Dialog.java:159)
at .gui.DialogManager.run(DialogManager.java:334)
at java.awt.event.InvocationEvent.dispatch(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access0(Unknown Source)
at java.awt.EventQueue.run(Unknown Source)
at java.awt.EventQueue.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.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)

我希望有人知道导致此异常的原因。我尝试运行 Java 1.7 和 1.8 中的扩展，但存在同样的问题。

此致

2016 年 8 月 16 日更新：如果我在 Netbeans Palette 上将 JTexPane 添加到设计器中，它就可以工作。只有构造函数中的初始化失败。

Answer 1

可能无法在不崩溃的情况下使用 Swing 完成此任务。相反，使用 com.sun.star.awt module. Complete examples are at http://api.libreoffice.org/examples/DevelopersGuide/examples.html#GraphicalUserInterfaces.

有关详细信息，请参阅 Creating Dialogs at Runtime。

还有一个link：This example确实使用了Swing。试试看是否会出现同样的问题。

Answer 2

我的肮脏解决方案是在 try-catch 中初始化 JTextPane 两次。因为在第二次通话中我没有得到异常。

创建 JTextPane 导致 NullPointerException - OpenOffice Extension

Creating JTextPane is leading to NullPointerException - OpenOffice Extension

java

swing

nullpointerexception

awt

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