1

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）。因为我怀疑这是一个我没有得到的概念，所以我没有包括一个，如果需要 MWS，请告诉我。

4

1 回答 1

4

不，不是。在您的三元运算符的表达式中：

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

SwingUtilities.isEventDispatchThread()正在返回true这就是它正在打印的原因"Out of EDT"。

对于表达式condition ? value1 : value2：如果condition为真，则结果为 ，value1否则为value2。

于 2013-10-29T19:12:03.967 回答