java - UncaughtExceptionHandler 未捕获异常

Question

我不确定为什么未调用 uncaughtException 方法。

static
{
    /**
     * Register a logger for unhandled exceptions.
     */
    Thread.UncaughtExceptionHandler globalExceptionHandler = new Thread.UncaughtExceptionHandler()
    {
        @Override
        public void uncaughtException(Thread t, Throwable e)
        {
            System.out.println("handle exception."); // can also set bp here that is not hit.
        }
    };

    Thread.setDefaultUncaughtExceptionHandler(globalExceptionHandler);
    Thread.currentThread().setUncaughtExceptionHandler(globalExceptionHandler);

    /**
     * Register gateway listen port.
     */
    try
    {
       // some stuff that raises an IOException
    }
    catch (IOException e)
    {
        System.out.println("Throwing exception");
        throw new RuntimeException(e);
    }

}

程序输出为:

抛出异常

java.lang.ExceptionInInitializerError
Caused by: java.lang.RuntimeException: java.io.FileNotFoundException: blah.jks 
    (The system cannot find the file specified)
...some stack trace...
Exception in thread "main" 
Process finished with exit code 1

Answer 1

RuntimeException 从静态初始值设定项中引发，它发生在加载主类时。然后它被系统类加载器捕获，将其包装到一个ExceptionInInitializerError中，然后从 JVM 退出。由于捕获了异常，因此永远不会调用默认的未捕获异常处理程序。