grails application shuts down as a result of caught exception in init - spring

Question

I have an grails 2.4.5 application that runs the init closure from bootstrap.groovy upon startup. It may throw an exception or it may not, but in either case, the application must continue running. What actually happens is during init() the app can't communicate with the server, a SocketTimeoutException is thrown by the underlying library and is then caught by my code. The caught exception unexpectedly causes the application to invoke destroy() and the application shuts down which I don't want. I expected that since the exception is caught, nothing wrong should be reported, and the application should remain running.
Here's the code using the RestTemplate library that causes the application to be destroyed. Without this code it remains running. The exception is caught and printed and then the app shuts down.
init = { servletContext ->
try {
// Send a post request
HttpHeaders headers = new HttpHeaders();
headers.add("Authorization", auth);
headers.add(HttpHeaders.CONTENT_TYPE, "application/json");
HttpEntity entity = new HttpEntity(headers);
HttpComponentsClientHttpRequestFactory httpRequestFactory = new HttpComponentsClientHttpRequestFactory();
httpRequestFactory.setConnectTimeout(10000);
httpRequestFactory.setReadTimeout(10000);
RestTemplate rt = new RestTemplate(httpRequestFactory);
ResponseEntity<String> rtString = rt.exchange(ME_URL + '/apps/register', HttpMethod.POST, entity, String.class);
} catch (Exception e) {
// don't rethrow
println e.getMessage(); // gets here, app is shutdown
}
}
I assumed this has something to do with the library I used (RestTemplate) so I also tried using the Unirest library. This also catches the exception but shuts down the application instead of continuing.
init = {
try {
res = Unirest
.post(ME_URL + '/apps/register')
.header('Authorization', auth)
.header('Content-Type', 'application/json')
.body([clientId: CLIENT_ID])
.asObject(Map.class);
} catch (Exception e) {
// don't rethrow
println e.getMessage(); // gets here, app is shutdown
}
}
Now I began to think that maybe exceptions are leaking from init(), so I tried to manually throw an exception on purpose to test this theory. I tried just a base Exception as well as the SocketTimeoutException that the previous two libraries threw. This is interesting because I've proven that this exception doesn't somehow "leak" out of grails init closure. This code below does NOT cause the application to shutdown and it remains running, which is what I want.
init = {
try {
throw new java.net.SocketTimeoutException("fake exception");
} catch (Exception e) {
// don't rethrow
println e.getMessage(); // gets here, but app continues
}
}
Generally the only thing printed out in the error log is a stacktrace for a java.net.SocketTimeoutException, and my own instrumentation code to show that destroy() is indeed being called.
2017-01-09 12:01:51,825 [localhost-startStop-1] ERROR StackTrace -
Full Stack Trace: XXX.YYY.ZZZ.AAA.GatewayException:
java.net.SocketTimeoutException: Read timed out at
XXX.YYY.ZZZ.registerApp(GatewayService.groovy:83) at
XXX.YYY.ZZZ.initApp(GatewayService.groovy:50) at
XXX.YYY.ZZZ.init(GatewayService.groovy:39) at
XXX.YYY.ZZZ.slientInit(GatewayService.groovy:30) at
XXX.YYY.ZZZ.BBB(Initializer.groovy:88) at
BootStrap$_closure1.doCall(BootStrap.groovy:17) at
grails.util.Environment.evaluateEnvironmentSpecificBlock(Environment.java:327)
at
grails.util.Environment.executeForEnvironment(Environment.java:320)
at
grails.util.Environment.executeForCurrentEnvironment(Environment.java:296)
at java.util.concurrent.FutureTask.run(FutureTask.java:266) at
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745) Caused by:
com.mashape.unirest.http.exceptions.UnirestException:
java.net.SocketTimeoutException: Read timed out at
com.mashape.unirest.http.HttpClientHelper.request(HttpClientHelper.java:143)
at
com.mashape.unirest.request.BaseRequest.asObject(BaseRequest.java:80)
at XXX.YYY.ZZZ.registerApp(GatewayService.groovy:71) ... 12 more
What I am looking for is:
Why this is happening
What I can do to fix this problem
If there's nothing I can do to fix my existing code, what is a workaround? Workarounds that I've tried: using PostContext annotation and also afterPropertiesSet method after extending InitializingBean. These two solutions do not work, as the init code I use will eventually use GORM, so GORM must be running at the time the code runs. During these two hooks, GORM is not ready (Or so that error messages say).
I am using grails 2.4.5.
One more thing: I have eliminated all my code in init except for the code you see above, so I am fairly sure that these REST calls getting exceptions is directly responsible for the application shutting down.
Any help greatly appreciated. Thanks!