当dumpStackTrace的第一个元素位于java.awt.EventDispatchThread.run时,为什么isEventDispatchThread()返回false?

    SwingUtilities.invokeLater(new Runnable() {

        @Override
        public void run() {
            doStuff();
        }
    });

    public void doStuff(){
       Thread.dumpStack();
       System.out.print(" [addToParents] "
           + ((SwingUtilities.isEventDispatchThread()
           ? "out of EDT" : " in EDT ")));
    }


产量:

[addToParents] out of EDT
java.lang.Exception: Stack trace
    at java.lang.Thread.dumpStack(Thread.java:1342)
    at pt.up.fe.dceg.neptus.gui.MissionBrowser.doStuff(MissionBrowser.java:899)
    at pt.up.fe.dceg.neptus.gui.MissionBrowser.access$6(MissionBrowser.java:883)
    at pt.up.fe.dceg.neptus.gui.MissionBrowser$3.run(MissionBrowser.java:1221)
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:251)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:721)
    at java.awt.EventQueue.access$200(EventQueue.java:103)
    at java.awt.EventQueue$3.run(EventQueue.java:682)
    at java.awt.EventQueue$3.run(EventQueue.java:680)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:691)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:244)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:163)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:147)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:139)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:97)


这是简化的代码(不是MWS)。我怀疑这是一个我没有理解的概念,如果没有MWS,请告诉我。

最佳答案

不,不是。在三元运算符的表达式中:

(SwingUtilities.isEventDispatchThread() ? "out of EDT" : " in EDT ")))


SwingUtilities.isEventDispatchThread()返回true,这就是为什么打印"Out of EDT"的原因。

对于表达式condition ? value1 : value2:如果condition为true,则结果为value1,否则结果为value2

08-04 14:09