0

我正在使用 Swing 构建一个使用数据库的应用程序。我有一个奇怪的问题，我不明白如何解决。

在某个面板中，我有一个组合框，我想使用数据库查询填充记录。在完成构建包含组合框的 JPanel 之后，我正在执行一个 Worker

private void populateLists(){
    GetSimpleRecordsWorker worker = new GetSimpleRecordsWorker(Tables.characters,panelLeftDetails);
    worker.execute();
}

它doInBackground执行 SELECT 查询，并在获得结果后 - 在 Worker 的done()方法中 - 更新面板的模型并调用面板的refreshFromModel.

charI.setSimpleModel(simpleModel);
charI.refreshFromModel();

refreshFromModel执行以下操作：

private void refreshFromSimpleModel(){
    charSelectCombo.removeAllItems();
    Pair[] pairs = simpleModel.getRecords();
    for (int i=0; i<pairs.length; i++){
        charSelectCombo.addItem(pairs[i]);
    }
    charSelectCombo.setSelectedItem(null);
}

现在，问题是，在它完成 refreshFromModel 之后 - GUI 卡住/冻结。我不知道为什么！奇怪的是，在不同的框架中，我使用了相同的方法——而且它没有问题。

此外，如果我尝试removeAll而不是removeAllItems它可以工作，但 ComboBox 会丢失它的箭头并且行为怪异。

我已经在调试器中进行了帧跟踪 - 那里有 removeSourceEvent 或 Unsafe.park 之类的东西。

 GUI.GuiHandler at localhost:53547 (Suspended)  
Daemon System Thread [Attach Listener] (Suspended)  
Daemon System Thread [Signal Dispatcher] (Suspended)    
Daemon System Thread [Finalizer] (Suspended)    
    Object.wait(long) line: not available [native method]   
    ReferenceQueue<T>.remove(long) line: not available  
    ReferenceQueue<T>.remove() line: not available  
    Finalizer$FinalizerThread.run() line: not available 
Daemon System Thread [Reference Handler] (Suspended)    
    Object.wait(long) line: not available [native method]   
    Reference$Lock(Object).wait() line: 485 
    Reference$ReferenceHandler.run() line: not available    
Thread [AWT-Shutdown] (Suspended)   
    Object.wait(long) line: not available [native method]   
    Object.wait() line: 485 
    AWTAutoShutdown.run() line: not available   
    Thread.run() line: not available    
Daemon System Thread [Java2D Disposer] (Suspended)  
    Object.wait(long) line: not available [native method]   
    ReferenceQueue<T>.remove(long) line: not available  
    ReferenceQueue<T>.remove() line: not available  
    Disposer.run() line: not available  
    Thread.run() line: not available    
Daemon Thread [AWT-Windows] (Suspended) 
    WToolkit.eventLoop() line: not available [native method]    
    WToolkit.run() line: not available  
    Thread.run() line: not available    
Thread [AWT-EventQueue-0] (Suspended)   
    EventQueue.removeSourceEvents(Object, boolean) line: not available  
    WindowsComboBoxUI$WindowsComboBoxRenderer(Component).removeNotify() line: not available 
    WindowsComboBoxUI$WindowsComboBoxRenderer(Container).removeNotify() line: not available 
    WindowsComboBoxUI$WindowsComboBoxRenderer(JComponent).removeNotify() line: not available    
    CellRendererPane(Container).remove(int) line: not available 
    CellRendererPane(Container).remove(Component) line: not available   
    WindowsComboBoxUI(BasicComboBoxUI).getSizeForComponent(Component) line: not available   
    WindowsComboBoxUI(BasicComboBoxUI).getDisplaySize() line: not available 
    WindowsComboBoxUI(BasicComboBoxUI).getMinimumSize(JComponent) line: not available   
    AutoCompleteComboBox(JComponent).getMinimumSize() line: not available   
    FlowLayout.minimumLayoutSize(Container) line: not available 
    JPanel(Container).minimumSize() line: not available 
    JPanel(Container).getMinimumSize() line: not available  
    JPanel(JComponent).getMinimumSize() line: not available 
    BoxLayout.checkRequests() line: not available   
    BoxLayout.minimumLayoutSize(Container) line: not available  
    JPanel(Container).minimumSize() line: not available 
    JPanel(Container).getMinimumSize() line: not available  
    JPanel(JComponent).getMinimumSize() line: not available 
    BoxLayout.checkRequests() line: not available   
    BoxLayout.preferredLayoutSize(Container) line: not available    
    JPanel(Container).preferredSize() line: not available   
    JPanel(Container).getPreferredSize() line: not available    
    JPanel(JComponent).getPreferredSize() line: not available   
    BorderLayout.layoutContainer(Container) line: not available 
    JPanel(Container).layout() line: not available  
    JPanel(Container).doLayout() line: not available    
    JPanel(Container).validateTree() line: not available    
    JPanel(Container).validateTree() line: not available    
    JPanel(Container).validateTree() line: not available    
    JLayeredPane(Container).validateTree() line: not available  
    JRootPane(Container).validateTree() line: not available 
    JRootPane(Container).validate() line: not available 
    RepaintManager.validateInvalidComponents() line: not available  
    SystemEventQueueUtilities$ComponentWorkRequest.run() line: not available    
    InvocationEvent.dispatch() line: not available  
    EventQueue.dispatchEvent(AWTEvent) line: not available  
    EventDispatchThread.pumpOneEventForFilters(int) line: not available 
    EventDispatchThread.pumpEventsForFilter(int, Conditional, EventFilter) line: not available  
    EventDispatchThread.pumpEventsForHierarchy(int, Conditional, Component) line: not available 
    EventDispatchThread.pumpEvents(int, Conditional) line: not available    
    EventDispatchThread.pumpEvents(Conditional) line: not available 
    EventDispatchThread.run() line: not available   
Thread [DestroyJavaVM] (Suspended)  
Daemon System Thread [D3D Screen Updater] (Suspended)   
    Object.wait(long) line: not available [native method]   
    D3DScreenUpdateManager.run() line: not available    
    Thread.run() line: not available    
Daemon System Thread [TimerQueue] (Suspended)   
    Object.wait(long) line: not available [native method]   
    TimerQueue.run() line: not available    
    Thread.run() line: not available    
Thread [Thread-3] (Suspended)   
    Thread.sleep(long) line: not available [native method]  
    JDCConnectionPool$ConnectionReaper.run() line: 93   
Daemon Thread [SwingWorker-pool-1-thread-1] (Suspended) 
    Unsafe.park(boolean, long) line: not available [native method]  
    LockSupport.park(Object) line: not available    
    AbstractQueuedSynchronizer$ConditionObject.await() line: not available  
    LinkedBlockingQueue<E>.take() line: not available   
    ThreadPoolExecutor.getTask() line: not available    
    ThreadPoolExecutor$Worker.run() line: not available 
    Thread.run() line: not available

非常感谢。

4

3 回答 3

1

它的 doInBackground 执行 SELECT 查询，并在获得结果后 - 更新面板的模型并调用面板的 refreshFromModel。

DB 查询在 doInBackground() 中完成。

模型的更新需要在 process() 方法中完成。

阅读 Swing 教程中关于并发的部分以获取更多信息。

于 2011-05-13T20:36:06.000 回答
1

向组合框中添加 100,000 个项目可能是问题的根源。

您还必须想知道一个用户如何可能处理组合框中的 100,000 个项目。

JComboBox通常不应该处理如此大量的项目。

优化代码的一种可能方法是显式调用setPrototypeDisplayValue()，这样，您可以避免JComboBox检查其所有模型项的尺寸来计算其自己的尺寸。这可能是您的系统看起来冻结的当前原因。

于 2011-05-15T09:59:18.057 回答
0

我了解您正在寻找具有大量建议的自动完成功能。

也许你可以看看glazedlists图书馆。它的核心功能是提供可观察列表，但它非常灵活。您可以做的一件事是基于这样的列表构建一个 ComboBoxModel 并启用组合框的自动完成功能（通过AutoCompleteSupport类）。

这种方法可以提供一种方法来避免 addItem 中任何与 ComboBox 相关的性能问题。那部分将被移入glazedlists。

于 2011-05-14T08:54:04.693 回答