没有stacktrace的线程异常

Question

I set up global exception handler:

Thread.setDefaultUncaughtExceptionHandler(new DefaultUncaughtExceptionHandler());

with quite simple implementation:

public class DefaultUncaughtExceptionHandler implements UncaughtExceptionHandler {

    public static final Logger logger = LoggerFactory.getLogger(DefaultUncaughtExceptionHandler.class);

    @Override
    public void uncaughtException(Thread t, Throwable e) {
        logger.error("Uncaught Exception detected in thread {}", t, e);
    }

}

sometimes I see in logs this exception several times:

[AWT-EventQueue-0] DefaultUncaughtExceptionHandler - Uncaught Exception detected in thread Thread[AWT-EventQueue-0,6,main]
java.lang.ArrayIndexOutOfBoundsException: null

but I cannot find where it comes from.

How do you think, why stacktrace is empty? It shouldn't be empty, all threads must be created at least from parent "main" thread or any other.

Answer 1

The JIT compiler can make some optimizations and "lose" stack traces.

You can use following JVM flag to disable this optimization:

-XX:-OmitStackTraceInFastThrow

Reference: http://jawspeak.com/2010/05/26/hotspot-caused-exceptions-to-lose-their-stack-traces-in-production-and-the-fix/