从扩展SwingWorker的内部类中触发事件

Question

我试图从内部类触发事件，但它不工作。这是我的代码:

抽象模型:

public abstract class AbstractModel {
    public PropertyChangeSupport propertyChangeSupport;
    public AbstractModel() {
        propertyChangeSupport = new PropertyChangeSupport(this);
    }
    public void addPropertyChangeListener(PropertyChangeListener listener) {
        propertyChangeSupport.addPropertyChangeListener(listener);
    }
    public void removePropertyChangeListener(PropertyChangeListener listener) {
        propertyChangeSupport.removePropertyChangeListener(listener);
    }
    protected void firePropertyChange(String propertyName, Object oldValue,
            Object newValue) {
        propertyChangeSupport.firePropertyChange(propertyName, oldValue,
                newValue);
    }
}

模型:

public class GUImodel extends AbstractModel {
    // Variables
    private final ArrayList tempResultsTable = new ArrayList();
    private static boolean done;
    //
    // RUN PROGRAM
    //
    public ArrayList run(ArrayList iF) {
        try {
            final BackgroundThread myThread = new BackgroundThread();
            myThread.init(iF);
            myThread.execute();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return tempResultsTable;
    }
    public void done() {
        System.out.println("done() called");
        boolean oldValue = done;
        done = true;
        firePropertyChange(GUIcontroller.DONE_PROPERTY, oldValue, done);
    }

    class BackgroundThread extends SwingWorker<Void, Void> {
        private ArrayList inputsFilesDataList;
        public void init(ArrayList iF) {
            inputsFilesDataList = iF;
            done = false;
        }
        @Override
        public Void doInBackground() throws Exception {
            for (int i = 0; i < inputsFilesDataList.size(); i++) {
                System.out.println(i);
            }
            return null;
        }
        @Override
        protected void done() {
            try {
                boolean oldValue = done;
                done = true;
                firePropertyChange(GUIcontroller.DONE_PROPERTY, oldValue, done);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
}

视图:

public class GUIview{
   ...
   public void propertyChange(final PropertyChangeEvent event) {
        if (event.getPropertyName().equals(GUIcontroller.DONE_PROPERTY)) {
            String newTab = (String)event.getNewValue();
            updateTab(newTab);
        }
   }
   ...
}

抽象控制器:

public abstract class AbstractController implements PropertyChangeListener {
    public final ArrayList<AbstractFrame> registeredViews;
    public final ArrayList<AbstractModel> registeredModels;
public AbstractController() {
    registeredViews = new ArrayList();
    registeredModels = new ArrayList();
}
public void addModel(AbstractModel model) {
    registeredModels.add(model);
    model.addPropertyChangeListener(this);
}
public void removeModel(AbstractModel model) {
    registeredModels.remove(model);
    model.removePropertyChangeListener(this);
}
public void addView(GUIview view) {
    registeredViews.add(view);
}
public void removeView(AbstractFrame view) {
    registeredViews.remove(view);
}
@Override
public void propertyChange(PropertyChangeEvent event) {
    for (AbstractFrame view : registeredViews) {
        view.propertyChange(event);
        }
    }
}

控制器

public class GUIcontroller extends AbstractController {
public static final String DONE_PROPERTY = "done";
ArrayList inputsFilesList = m_model.loadFromExcel();    
    @Override
    public void propertyChange(PropertyChangeEvent event) {
        if (event.getPropertyName().equals(GUIcontroller.DONE_PROPERTY)) {          
            m_view.getResultsModel().updateResultsTableDataList(
                    m_model.getTempResultsTable());
        } else {
            for (AbstractFrame view : registeredViews) {
                view.propertyChange(event);
            }
        }
    }
     public runProgram(){
          m_model.run(inputsFilesList);
     }

}

主。

public class GUImain {
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    createGUI();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }
    public static void createGUI() {
        InputsModel inputsModel = new InputsModel();
        ResultsModel resultsModel = new ResultsModel();
        GUImodel model = new GUImodel();
        GUIcontroller controller = new GUIcontroller();
        controller.addModel(model);
        GUIview view = new GUIview(controller, model, inputsModel, resultsModel);
        controller.addControllerListerners();
        view.setVisible(true);
    }
}

你知道是什么问题吗?

我需要在后台线程中运行一些方法，因此我使用了一个扩展SwingWorker的内部类。一旦线程完成，我需要触发一个事件向控制器报告一些更改。

done()方法中的"firePropertyChange(…)"行没有被执行。

相关问题:如果某个类ClassA扩展了ClassAA，它的内部类ClassB扩展了ClassBB，那么内部类ClassB是否也扩展了ClassAA ?

Answer 1

A $$ guess:

您是否将侦听器添加到正确的SwingPropertyChangeSupport对象?这必须是AbstractModel持有的对象，而不是BackgroundThread持有的对象。换句话说，要使侦听器能够接收属性已更改的通知，它们必须将PropertyChangeListener添加到AbstractModel中，并且BackgroundThread类必须具有执行此操作的方法。

(编辑)
或者从AbstractModel类中去掉PropertyChangeSupport，按照mKorbel的建议，只使用SwingWorker持有的PropertyChangeSupport。

否则，你的问题严重缺乏代码/信息，无法在当前状态下给出真正有知识的答案，我们所能做的就是猜测可能存在的问题及其答案。在这里提问时，请考虑我们的观点，问问自己需要哪些信息才能让别人完全理解问题并回答问题。

---

2

您的代码证明了我的假设实际上是正确的，您正在将PropertyChangeListener添加到错误的PropertyChangeSupport对象中，因此SwingWorker中的通知—从未将PropertyChangeListener分配给其支持—将不会对已添加到AbstractModel支持对象中的侦听器产生影响。

:

firePropertyChange(GUIcontroller.DONE_PROPERTY, oldValue, done);

是在SwingWorker的SwingPropertyChangeSupport对象上调用的，而不是在AbstractModel的对象上调用的。

一个可能的解决方案是将您的fire方法更改为:

GUImodel.this.firePropertyChange(GUIcontroller.DONE_PROPERTY, oldValue, done);

以便正确的支持对象通知正确的侦听器。

---

编辑3
我的SSCCE(比真正的SSCCE长一点)证明了我的论点:

import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import javax.swing.AbstractAction;
import javax.swing.Action;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingWorker;
import javax.swing.event.SwingPropertyChangeSupport;
public class MvcSscce {
   public static void main(String[] args) {
      EventQueue.invokeLater(new Runnable() {
         public void run() {
            try {
               createGUI();
            } catch (Exception e) {
               e.printStackTrace();
            }
         }
      });
   }
   public static void createGUI() {
      GUImodel model = new GUImodel();
      GUIcontroller controller = new GUIcontroller();
      controller.addModel(model);
      GUIview view = new GUIview(controller);
      view.setVisible(true);
   }
}
class GUIview {
   private JPanel mainPanel = new JPanel();
   private JFrame frame = new JFrame("Fubar");
   public GUIview(AbstractController controller) {
      mainPanel.add(new JButton(controller.getButtonAction()));
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.getContentPane().add(mainPanel);
      frame.pack();
      frame.setLocationRelativeTo(null);
   }
   public void setVisible(boolean visible) {
      frame.setVisible(visible);
   }
}
abstract class AbstractModel {
   // note this should be a SwingPropertyChangeSupport
   public SwingPropertyChangeSupport propertyChangeSupport;
   public abstract void run();
   public AbstractModel() {
      propertyChangeSupport = new SwingPropertyChangeSupport(this);
   }
   public void addPropertyChangeListener(PropertyChangeListener listener) {
      propertyChangeSupport.addPropertyChangeListener(listener);
   }
   public void removePropertyChangeListener(PropertyChangeListener listener) {
      propertyChangeSupport.removePropertyChangeListener(listener);
   }
   protected void firePropertyChange(String propertyName, Object oldValue,
         Object newValue) {
      propertyChangeSupport.firePropertyChange(propertyName, oldValue, newValue);
   }
}
class GUImodel extends AbstractModel {
   private boolean done = false;
   public void run() {
      done = false;
      final BackgroundThread myThread = new BackgroundThread();
      myThread.execute();
   }
   private class BackgroundThread extends SwingWorker<Void, Void> {
      private static final long SLEEP_TIME = 2000;
      @Override
      protected Void doInBackground() throws Exception {
         Thread.sleep(SLEEP_TIME);
         return null;
      }
      @Override
      protected void done() {
         System.out.println("done() called");
         boolean oldValue = done;
         done = true;
         // fire both property change listeners and see what gets notified
         firePropertyChange(GUIcontroller.DONE_PROPERTY, oldValue, done);
         GUImodel.this.firePropertyChange(GUIcontroller.DONE_PROPERTY_2,
               oldValue, done);
      }
   }
}
class AbstractController implements PropertyChangeListener {
   private AbstractModel model;
   public void addModel(AbstractModel model) {
      this.model = model;
      model.addPropertyChangeListener(this);
   }
   public Action getButtonAction() {
      @SuppressWarnings("serial")
      Action buttonAction = new AbstractAction("Press Me") {
         @Override
         public void actionPerformed(ActionEvent arg0) {
            model.run();
         }
      };
      return buttonAction;
   }
   @Override
   public void propertyChange(PropertyChangeEvent evt) {
      String output = String.format("Evt: %s, newValue: %s",
            evt.getPropertyName(), evt.getNewValue());
      System.out.println(output);
   }
}
class GUIcontroller extends AbstractController {
   public static final String DONE_PROPERTY_2 = "done property 2";
   public static final String DONE_PROPERTY = "done property";
}

请注意，在2秒延迟之后，侦听器会收到通知，但只是DONE_PROPERTY_2属性，而不是DONE_PROPERTY。

Answer 2

• 添加PropertyChangeListener到SwingWorker的实例，并且没有为SwingWorker实现另一个Swing Listener

• SwingWorker从PropertyChangeListener返回DONE, PENDING, STARTED事件

• 从public void propertyChange(PropertyChangeEvent event) {你可以分发适当的通知(s)到Model，到View，因为done(), process(), publish()保证输出在Event Dispatch Thread上完成