Java SwingWorker掛

Question

我正在調試一些使用SwingWorker編寫的代碼，以執行數值計算和GUI更新的混合。 SwingWorker掛起並帶有以下堆棧跟蹤：

Full thread dump Java HotSpot(TM) Client VM (14.3-b01 mixed mode, sharing):

"SwingWorker-pool-3-thread-4" prio=6 tid=0x07fd7c00 nid=0x143c waiting on condition [0x0a33f000]
   java.lang.Thread.State: TIMED_WAITING (sleeping)
        at java.lang.Thread.sleep(Native Method)
        at sum.ee.ui.modelviewer.ModelViewer$ModelAnimator.doInBackground(ModelViewer.java:940)
        at sum.ee.ui.modelviewer.ModelViewer$ModelAnimator.doInBackground(ModelViewer.java:877)
        at javax.swing.SwingWorker$1.call(SwingWorker.java:274)
        at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
        at java.util.concurrent.FutureTask.run(FutureTask.java:138)
        at javax.swing.SwingWorker.run(SwingWorker.java:313)
        at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
        at java.lang.Thread.run(Thread.java:619)

"SwingWorker-pool-3-thread-3" prio=6 tid=0x07fd7000 nid=0x11a8 waiting for monitor entry [0x0a2af000]
   java.lang.Thread.State: BLOCKED (on object monitor)
        at java.awt.Component.resize(Component.java:2044)
        - waiting to lock <0x24b936a0> (a java.awt.Component$AWTTreeLock)
        at java.awt.Component.setSize(Component.java:2035)
        at java.awt.Component.resize(Component.java:2069)
        at java.awt.Component.setSize(Component.java:2060)
        at javax.swing.JViewport.setViewSize(JViewport.java:1038)
        at javax.swing.ViewportLayout.layoutContainer(ViewportLayout.java:183)
        at java.awt.Container.layout(Container.java:1421)
        at java.awt.Container.doLayout(Container.java:1410)
        at jsyntaxpane.components.LineNumbersRuler.updateSize(LineNumbersRuler.java:109)
        at jsyntaxpane.components.LineNumbersRuler.removeUpdate(LineNumbersRuler.java:203)
        at javax.swing.text.AbstractDocument.fireRemoveUpdate(AbstractDocument.java:243)
        at jsyntaxpane.SyntaxDocument.fireRemoveUpdate(SyntaxDocument.java:118)
        at javax.swing.text.AbstractDocument.handleRemove(AbstractDocument.java:608)
        at javax.swing.text.AbstractDocument.remove(AbstractDocument.java:576)
        at javax.swing.JEditorPane.setText(JEditorPane.java:1493)
        at sum.ee.ui.SourceCodePanel.clearSourcePane(SourceCodePanel.java:256)
        at sum.ee.ui.SourceCodePanel.access$100(SourceCodePanel.java:47)
        at sum.ee.ui.SourceCodePanel$1.stateChanged(SourceCodePanel.java:209)
        at sum.ee.ui.VisualizationAggregator.fireStateChanged(VisualizationAggregator.java:300)
        at sum.ee.ui.VisualizationAggregator.update(VisualizationAggregator.java:97)
        at sum.ee.ui.modelviewer.ModelViewer$ModelAnimator.doInBackground(ModelViewer.java:918)
        at sum.ee.ui.modelviewer.ModelViewer$ModelAnimator.doInBackground(ModelViewer.java:877)
        at javax.swing.SwingWorker$1.call(SwingWorker.java:274)
        at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
        at java.util.concurrent.FutureTask.run(FutureTask.java:138)
        at javax.swing.SwingWorker.run(SwingWorker.java:313)
        at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
        at java.util.concurrent.ThreadPoolExecutor

$ Worker.run（ThreadPoolExecutor.java:908）在java.lang.Thread.run（Thread.java:619）

我的理解是GUI工作不應在doInBackground（）內部完成，而應在done（）中完成。 我進行了一個幼稚的實驗，將doInBackground（）中的所有代碼都移到了done（）中，但仍然無法正常工作。 在此問題上，人們是否可以給我一些提示，以幫助我扎根？ 代碼如下：

protected Void doInBackground() {
    isAnimating = true;
    resetButtonBackgrounds();
    backgroundColor = new Color(175, 255, 175);  // Soft Green

    JToggleButton b = null;
    for (final int index : modelIndices) {
        if (index == modelIndices.get(modelIndices.size() - 1)) {
            backgroundColor = defaultBackgroundColor;
        }
        if (!keepTrace) {
            // Resetting the backgrounds is necessary to have
            // individual display of the changing elements due to
            // the fact that there can be multiple nodes per
            // source line.  The reset works in combination
            // with updating from ModelViewer.this (as opposed
            // to the 'this' of ModelAnimator instances) due
            // to not sending an event to itself.  Furthermore,
            // if the event was sent from ModelAnimator, the model
            // indices are recalculated, causing a jump when multiple
            // element source lines are encountered.
            resetButtonBackgrounds();
        }
        aggregator.modelIndex(index);
        aggregator.update(ModelViewer.this);

        b = getButtonByIndex(index);
        scrollRectToVisible(b.getBounds());
        ModelViewer.this.repaint();
        try {
            StaticTools.sleepAtLeast(sleepTimeMilliseconds);
        } catch (final InterruptedException ex) {
            // continue with thread
        }
    }

    isAnimating = false;

    if ( b != null) {

        Color orig = b.getBackground();
        Color blink = Color.PINK;
        Color current = orig;
        for (int i = 0; i < 100; i++) {

            try {
                Thread.sleep(100);
            } catch (InterruptedException ex) {
            }

            if (current == orig) {
                current = blink;
            } else {
                current = orig;
            }

            b.setBackground(current);
            ModelViewer.this.repaint();

        }
    }

    return null;
}

另一個線索是有兩個執行的SwingWorker線程。 他們可以運行同一線程嗎？

更新：這是執行SwingWorker的代碼：

public final void animate（final long delayBetweenUpdatesMilliseconds，final List modelIndices，final boolean keepTrace，final List propertyChangeListeners）{

ModelAnimator modelAnimator =
        new ModelAnimator(delayBetweenUpdatesMilliseconds, modelIndices,
        keepTrace);
for (final PropertyChangeListener listener : propertyChangeListeners) {
    modelAnimator.addPropertyChangeListener(listener);
}

modelAnimator.execute();

}

Answer 1

未能遵守Swing EDT規則。

SwingWorker的目的是在發生UI事件時執行繁重的nonGUI任務，否則將阻塞UI，然后最后更新UI。

因此，您可以在doInBackground（）;內部實現舉重。 然后，一旦揮桿完成，就會在EDT上調用done（），然后您可以使用get（）檢索結果。

這里的問題是您正在SwingWorker創建的新線程中進行GUI工作。 這可能導致死鎖和並發問題。

這包括創建所述GUI對象，即使您已經在EDT上，它也應該處於可運行狀態

動作如下：

b = getButtonByIndex(index);

應該用InvokeandWait封裝在Runnable中。 實際上修改GUI本身的東西尤其需要放在自己的可運行對象中， 即使您已經在swing事件分配線程中響應按鈕的按下或更改，您也冒着對已經在處理的對象進行操作的風險。

例如，秋千正在上鎖並鎖定A，以便您進行工作，而B則嘗試鎖定並在A上工作