java - 网络浏览器中的 IllegalThreadStateException(Windows)

Question

我收到 IllegalThreadStateException。

在 Eclipse 的调试器下一切正常，但当我尝试在 Firefox 上测试它时，它开始失败。第一次运行正常，刷新网页后出现异常。

这是代码:

public void init() {
    try {           
        SwingUtilities.invokeAndWait(new Runnable() 
        {
            public void run() 
            {                   
                createGUI();
                createConnection();
            }
        });
    } 
    catch (Exception e) 
    { 
        System.err.println("createGUI didn't complete successfully");
        e.printStackTrace();
        System.err.println(e.toString());
    }
}


private void createConnection()
{       
    _connectionThread = ConnectionThread.getInstance();
    _connectionThread.setServer(getCodeBase().getHost());
    _connectionThread.start(); <------ Exception        
}

我是 Java 新手，老实说，这是我的第一个小程序。我知道我做错了什么，但我找不到它是什么。

编辑:从控制台

java.lang.reflect.InvocationTargetException
at java.awt.EventQueue.invokeAndWait(Unknown Source)
at javax.swing.SwingUtilities.invokeAndWait(Unknown Source)
at com.onlinegame.gameclient.GameClient.init(GameClient.java:76)
at com.sun.deploy.uitoolkit.impl.awt.AWTAppletAdapter.init(Unknown Source)
at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.IllegalThreadStateException
    at java.lang.Thread.start(Unknown Source)
    at com.onlinegame.gameclient.GameClient.createConnection(GameClient.java:175)
    at com.onlinegame.gameclient.GameClient.access$100(GameClient.java:34)
    at com.onlinegame.gameclient.GameClient$1.run(GameClient.java:81)
    at java.awt.event.InvocationEvent.dispatch(Unknown Source)
    at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
    at java.awt.EventQueue.access$200(Unknown Source)
    at java.awt.EventQueue$3.run(Unknown Source)
    at java.awt.EventQueue$3.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
    at java.awt.EventQueue.dispatchEvent(Unknown Source)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.run(Unknown Source)
java.lang.reflect.InvocationTargetException

Answer 1

 _connectionThread = ConnectionThread.getInstance();

看起来 ConnectionThread 是一个单例(这是真的吗？)并且扩展了 Thread。如果这是正确的，您可能会遇到问题，因为线程只能启动一次( Thread.start() )。如果您尝试第二次启动同一个 Thread 实例，它将失败并抛出 java.lang.IllegalThreadStateException。

要解决这个问题，请在每个请求上创建一个新的 Thread 对象，或者将执行结果缓存在单例中。如何准确实现取决于您想要通过线程实现什么以及应用程序的设计。