JavaFX TextArea.使用追加文本太快时应用程序崩溃.任何建议

Question

我正在更新javafx.scene.control的字符串内容。来自不同线程的文本区域，在当时添加一个句子。

这是我的侦听器方法，我从中追加到文本区域（命名显示）：

public void onStatus(Status status) {
        if(userFilters.statusMatches(status)){
             display.appendText("@"
                 + status.getUser().getScreenName() + "n"
                 + status.getText() + "n-------------n");
        }
}

如果发布速度不是太快，它就可以了。

否则，如果传入的消息太多（例如，从社交网络获取的公共帖子），应用程序"图形更新"会在其中几条消息后崩溃。

异常不是指我编写的代码的任何元素。所以我不知道如何捕获它们并以某种干净的方式停止应用程序。

（顺便说一下，我不是要附加空元素。

这些是例外：

Exception in thread "JavaFX Application Thread" java.lang.NullPointerException
at com.sun.javafx.text.PrismTextLayout.getRuns(PrismTextLayout.java:236)
at javafx.scene.text.Text.getRuns(Text.java:317)
at javafx.scene.text.Text.updatePGText(Text.java:1465)
at javafx.scene.text.Text.impl_updatePeer(Text.java:1500)
at javafx.scene.Node.impl_syncPeer(Node.java:503)
at javafx.scene.Scene$ScenePulseListener.synchronizeSceneNodes(Scene.java:2290)
at javafx.scene.Scene$ScenePulseListener.pulse(Scene.java:2419)
at com.sun.javafx.tk.Toolkit.lambda$runPulse$30(Toolkit.java:314)
at com.sun.javafx.tk.Toolkit$$Lambda$122/1010826311.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.Toolkit.runPulse(Toolkit.java:313)
at com.sun.javafx.tk.Toolkit.firePulse(Toolkit.java:340)
at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:525)
at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:505)
at com.sun.javafx.tk.quantum.QuantumToolkit.lambda$runToolkit$400(QuantumToolkit.java:334)
at com.sun.javafx.tk.quantum.QuantumToolkit$$Lambda$41/1654631781.run(Unknown Source)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
Exception in thread "JavaFX Application Thread" java.lang.NullPointerException
at com.sun.javafx.text.PrismTextLayout.addTextRun(PrismTextLayout.java:755)
at com.sun.javafx.text.GlyphLayout.addTextRun(GlyphLayout.java:121)
at com.sun.javafx.text.GlyphLayout.breakRuns(GlyphLayout.java:191)
at com.sun.javafx.text.PrismTextLayout.buildRuns(PrismTextLayout.java:770)
at com.sun.javafx.text.PrismTextLayout.layout(PrismTextLayout.java:1021)
at com.sun.javafx.text.PrismTextLayout.ensureLayout(PrismTextLayout.java:223)
at com.sun.javafx.text.PrismTextLayout.getBounds(PrismTextLayout.java:246)
at javafx.scene.text.Text.getLogicalBounds(Text.java:358)
at javafx.scene.text.Text.impl_computeGeomBounds(Text.java:1168)
at javafx.scene.Node.updateGeomBounds(Node.java:3556)
at javafx.scene.Node.getGeomBounds(Node.java:3509)
at javafx.scene.Node.getLocalBounds(Node.java:3457)
at javafx.scene.Node$MiscProperties$2.computeBounds(Node.java:6451)
at javafx.scene.Node$LazyBoundsProperty.get(Node.java:9285)
at javafx.scene.Node$LazyBoundsProperty.get(Node.java:9255)
at javafx.scene.Node.getBoundsInLocal(Node.java:3135)
at com.sun.javafx.scene.control.skin.TextAreaSkin$ContentView.layoutChildren(TextAreaSkin.java:207)
at javafx.scene.Parent.layout(Parent.java:1076)
at javafx.scene.Parent.layout(Parent.java:1082)
at javafx.scene.Parent.layout(Parent.java:1082)
at javafx.scene.Parent.layout(Parent.java:1082)
at javafx.scene.Parent.layout(Parent.java:1082)
at javafx.scene.Parent.layout(Parent.java:1082)
at javafx.scene.Parent.layout(Parent.java:1082)
at javafx.scene.Scene.doLayoutPass(Scene.java:552)
at javafx.scene.Scene$ScenePulseListener.pulse(Scene.java:2397)
at com.sun.javafx.tk.Toolkit.lambda$runPulse$30(Toolkit.java:314)
at com.sun.javafx.tk.Toolkit$$Lambda$122/1010826311.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.Toolkit.runPulse(Toolkit.java:313)
at com.sun.javafx.tk.Toolkit.firePulse(Toolkit.java:340)
at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:525)
at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:505)
at com.sun.javafx.tk.quantum.QuantumToolkit.lambda$runToolkit$400(QuantumToolkit.java:334)
at com.sun.javafx.tk.quantum.QuantumToolkit$$Lambda$41/1654631781.run(Unknown Source)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
at com.sun.javafx.text.PrismTextLayout.layout(PrismTextLayout.java:1063)
at com.sun.javafx.text.PrismTextLayout.ensureLayout(PrismTextLayout.java:223)
at com.sun.javafx.text.PrismTextLayout.getBounds(PrismTextLayout.java:246)
at javafx.scene.text.Text.getLogicalBounds(Text.java:358)
at javafx.scene.text.Text.impl_computeGeomBounds(Text.java:1168)
at javafx.scene.Node.updateGeomBounds(Node.java:3556)
at javafx.scene.Node.getGeomBounds(Node.java:3509)
at javafx.scene.Node.getLocalBounds(Node.java:3457)
at javafx.scene.Node.updateTxBounds(Node.java:3620)
at javafx.scene.Node.getTransformedBounds(Node.java:3403)
at javafx.scene.Node.updateBounds(Node.java:538)
at javafx.scene.Parent.updateBounds(Parent.java:1706)
at javafx.scene.Parent.updateBounds(Parent.java:1706)
at javafx.scene.Parent.updateBounds(Parent.java:1706)
at javafx.scene.Parent.updateBounds(Parent.java:1706)
at javafx.scene.Parent.updateBounds(Parent.java:1706)
at javafx.scene.Parent.updateBounds(Parent.java:1706)
at javafx.scene.Parent.updateBounds(Parent.java:1706)
at javafx.scene.Parent.updateBounds(Parent.java:1706)
at javafx.scene.Scene$ScenePulseListener.pulse(Scene.java:2404)
at com.sun.javafx.tk.Toolkit.lambda$runPulse$30(Toolkit.java:314)
at com.sun.javafx.tk.Toolkit$$Lambda$122/1010826311.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.Toolkit.runPulse(Toolkit.java:313)
at com.sun.javafx.tk.Toolkit.firePulse(Toolkit.java:340)
at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:525)
at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:505)
at com.sun.javafx.tk.quantum.QuantumToolkit.lambda$runToolkit$400(QuantumToolkit.java:334)
at com.sun.javafx.tk.quantum.QuantumToolkit$$Lambda$41/1654631781.run(Unknown Source)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
Exception in thread "JavaFX Application Thread" java.lang.ArrayIndexOutOfBoundsException
Exception in thread "JavaFX Application Thread" java.lang.ArrayIndexOutOfBoundsException
Exception in thread "JavaFX Application Thread" java.lang.ArrayIndexOutOfBoundsException
Exception in thread "JavaFX Application Thread" java.lang.ArrayIndexOutOfBoundsException
Exception in thread "JavaFX Application Thread" java.lang.ArrayIndexOutOfBoundsException

（...等等...

Answer 1

抛出这两个异常是因为变量 lines 在 PrismTextLayout 内为 null。为什么这为空？每次在此方法中将文本追加到文本区域时，它都设置为 null（由 append 调用）：

com.sun.javafx.text.PrismTextLayout.reset(PrismTextLayout.java:92)

lines var 通常不为 null，因为每次渲染场景时都会重置场景。您之所以获得此 NPE，是因为您在设置为 null lines 和重置为其正常值之间调用。

解决方案是从 JavaFX 应用程序线程调用append（即使用 runLater(() -> ...) 附加到 TA）。