Java：IEventBroker零點異常

我想在按下JButton時在我的RCP項目中發佈一個事件。爲此我嘗試使用IEventBroker。Java：IEventBroker零點異常

我跟着從vogella.com here教程。

@Inject 
private IEventBroker eventBroker; 

@Override 
    public void actionPerformed(ActionEvent arg0) { 

     // THE UPDATE BUTTON 
     if (arg0.getSource()== update) { 

      System.out.println("Button Pressed"); 

      eventBroker.post("test", "New data"); // generates a null point exception 
      ..... 
      .....

不幸的是，這會產生一個零點異常。

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException 
at chipcoach.tableviewerDMA.GanttFrame.actionPerformed(GanttFrame.java:522) 
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source) 
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source) 
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source) 
at javax.swing.DefaultButtonModel.setPressed(Unknown Source) 
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source) 
at java.awt.Component.processMouseEvent(Unknown Source) 
at javax.swing.JComponent.processMouseEvent(Unknown Source) 
at java.awt.Component.processEvent(Unknown Source) 
at java.awt.Container.processEvent(Unknown Source) 
at java.awt.Component.dispatchEventImpl(Unknown Source) 
at java.awt.Container.dispatchEventImpl(Unknown Source) 
at java.awt.Component.dispatchEvent(Unknown Source) 
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source) 
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source) 
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source) 
at java.awt.Container.dispatchEventImpl(Unknown Source) 
at java.awt.Window.dispatchEventImpl(Unknown Source) 
at java.awt.Component.dispatchEvent(Unknown Source) 
at java.awt.EventQueue.dispatchEventImpl(Unknown Source) 
at java.awt.EventQueue.access$400(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.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source) 
at java.awt.EventQueue$4.run(Unknown Source) 
at java.awt.EventQueue$4.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)

在本教程的後面部分，它也沒有說明@EventTopic和@UIEventTopic註釋是在哪裏定義的。

來源

2014-10-29 2c00L

那麼想必注入工作不填充'eventBroker'。你使用調試器來驗證？ – 2014-10-29 17:32:56

你是如何創建這個課程的？ Eclipse僅對從應用程序模型創建的對象進行注入。 – 2014-10-29 17:35:28

如何驗證注射不起作用？請原諒我缺乏知識。 :) 此類用於繪製甘特圖：公共類GanttFrame延伸ApplicationFrame實現MouseWheelListener的，的ChangeListener，AxisChangeListener，ActionListener的{ 。然後通過AWT框架添加到視圖組合中 Composite composite = new Composite（scrolledComposite，SWT.EMBEDDED | SWT.NO_BACKGROUND）; frame = SWT_AWT.new_Frame（composite）; – 2c00L 2014-10-29 17:40:25

Christian在Event Broker上絕對出色的tutorial解決了我如何在RCP項目中使用Event Broker的問題。

以下相關需要添加：

org.eclipse.e4.core.services 
org.eclipse.osgi.services

來源

2014-11-04 11:37:35 2c00L

Java：IEventBroker零點異常

回答

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