/** Demonstrate how to handle an Exception from an asynchronous call. */
private void callAsyncWithFailure() throws InterruptedException {
Future<String> x;
try {
x =
accessBean
.failure(); // this method will return successfully, because the invocation will be
// successful!
} catch (IllegalAccessException e) {
throw new RuntimeException("Unexpected failure during start asynchronous execution!", e);
}
try {
x.get(); // this will not return successfully
} catch (ExecutionException e) {
// the IllegalAccessException is thrown by the bean method
if (e.getCause() instanceof IllegalAccessException) {
// This is the expected behavior
LOGGER.info("Catch the expected Exception of the asynchronous execution!");
} else if (e.getCause().getCause() instanceof IllegalAccessException) {
LOGGER.info(
"Catch the covered Exception of the asynchronous execution, you may be using an older release of JBoss EAP!");
} else {
throw new RuntimeException("Unexpected ExecutionException during asynchronous call!", e);
}
}
}
/**
* Demonstrate a fire-and-forget call to an asynchronous bean.
*
* @throws InterruptedException
*/
private void fireAndForget() throws InterruptedException {
long sleepMillis = 15000;
accessBean.fireAndForget(sleepMillis);
LOGGER.info(
String.format(
"The server log should contain a message at (about) %s, indicating that the call to the asynchronous bean completed.",
new Date(new Date().getTime() + sleepMillis)));
}
/**
* Demonstrate how to call an asynchronous EJB and continue local work meanwhile. After finishing
* local work wait for the result of the server call.<br>
* Remember that the call of Future.get() will have a remote roundtrip to the server.
*/
private void waitForAsyncResult()
throws InterruptedException, ExecutionException, TimeoutException {
Future<String> myResult = accessBean.longerRunning(1500); // Start a call with a short duration
// you might do something here
// get() without a timeout will wait until the remote result is present.
LOGGER.info("Got the async result as expected after wait => " + myResult.get());
}
/**
* Demonstrate how to call an asynchronous EJB, and then perform another task whilst waiting for
* the result. If the result is not present after the timeout of get(<timeout>) the result will be
* ignored.
*
* @throws TimeoutException Will be thrown if you change the timing
*/
private void getResultAsync() throws InterruptedException, ExecutionException, TimeoutException {
Future<String> myResult = accessBean.longerRunning(200); // Start a call with a short duration
// simulate something
// wait below 200ms will force a timeout during get
Thread.sleep(400);
// If you handle the TimeoutException you are able to ignore the result
// WARNING: there might be an ERROR at server side that the result is not delivered
LOGGER.info("Got the async result as expected => " + myResult.get(1, TimeUnit.MILLISECONDS));
}
