Java Swing中有关事件机制

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看到过两种方式启动主窗体的代码：

方式1：

        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new MainJFrame().setVisible(true);
            }
        });

方式2

        javax.swing.SwingUtilities.invokeLater(new Runnable() {
			@Override
			public void run() {
				new MainJFrame().setVisible(true);
			}
		});

SwingUtilities.invokeLater和EventQueue.invokeLater实际上是一样的。SwingUtilities.invokeLater实际上是调用EventQueue.invokeLater。

JDK源码

    public static void invokeLater(Runnable doRun) {
        EventQueue.invokeLater(doRun);
    }

SwingUtilities.invokeLater的Javadoc有这样的一段说明：

Open Declaration void javax.swing.SwingUtilities.invokeLater(Runnable doRun)

Causes doRun.run() to be executed asynchronously on the AWT event dispatching thread(就是EDT). This will happen after all pending AWT events have been processed. This method should be used when an application thread needs to update the GUI. In the following example the invokeLater call queues the Runnable object doHelloWorld on the event dispatching thread and then prints a message.

Runnable doHelloWorld = new Runnable() {
　　public void run() {
　　　　System.out.println("Hello World on " + Thread.currentThread());
　　}
};

SwingUtilities.invokeLater(doHelloWorld);
System.out.println("This might well be displayed before the other message.");

If invokeLater is called from the event dispatching thread -- for example, from a JButton‘s ActionListener -- the doRun.run() will still be deferred until all pending events have been processed. Note that if the doRun.run() throws an uncaught exception the event dispatching thread will unwind (not the current thread).
Additional documentation and examples for this method can be found in Concurrency in Swing.

As of 1.3 this method is just a cover for java.awt.EventQueue.invokeLater().

Unlike the rest of Swing, this method can be invoked from any thread.
Parameters:doRun See Also:invokeAndWait

 Event Dispatching Thread就是常说的EDT，事件派发线程

关于事件分发的机制，参看下面的这篇文章，讲的还是比较全面的。

http://blog.itpub.net/13685345/viewspace-374940/

Java Swing中有关事件机制

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原文地址：http://www.cnblogs.com/xiaozu/p/4498803.html