It is my event publisher.
public void evnetMaker(){
List<MyType> messages = ...;
System.out.println("Event publish");
applicationEventPublisher.publishEvnet(messages);
System.out.println("End Event");
}
It is eventListener.
#EventListener
public void listenEvent(List<MyType> messages){
System.out.println("Listen");
}
I expect
Event publish
Listen
End Event
But actual
Event publish
End Event
I think evnet listener can't handle List<>.
So I fixed it like this.
public void evnetMaker(){
List<MyType> messages = ...;
...
applicationEventPublisher.publishEvnet(new CustomEvent(messages));
...
}
and
#EventListener
public void listenEvent(CustomEvent customEvent){
...
customEvent.getMessages();
...
}
It works well.
I wonder that why spring #EventListener doesn't work when parameter is List<>.
Related
I have a spring-boot application that implements a camel routing service. I want to know if the consumers queues are alive or not (because those queues are not in my system). I implemented a Event Notifier to know if the exchange sent event it's triggered or not. But my custom implementation of the Event notifier is not working. I can see in the logs when camel context event is triggered but this is all. No other event is captured by the event notifier.
Thanks.
This is may event notifier class:
#Component
public class MyLoggingSentEventNotifer extends EventNotifierSupport {
private static final Logger logger = LoggerFactory.getLogger(MyLoggingSentEventNotifer.class);
#Override
public void notify(final EventObject event) throws Exception {
if (event instanceof CamelContextStartedEvent) {
}
if (event instanceof ExchangeSentEvent) {
final ExchangeSentEvent sent = (ExchangeSentEvent) event;
log.info("Took {} millis to send to: {}", sent.getTimeTaken(), sent.getEndpoint());
}
if (event instanceof ExchangeCreatedEvent) {
final ExchangeSendingEvent sending = (ExchangeSendingEvent) event;
log.info("Sending to to: {}", sending.getEndpoint());
}
}
#Override
public boolean isEnabled(final EventObject event) {
if (event instanceof CamelContextStartedEvent) {
return true;
}
return false;
}
}
The problem is your isEnabled method where you should filter which events you want to accept. And in your code, you only accept the camel context started event, and therefore you only get that. Instead either just return true for all events, or filter the ones you only want.
I am experiencing an odd behavior of my spring boot websocket set-up.
Sometimes it works, sometimes it doesn't, it just feels random.
I have tried the several setups, none proved solid: I moved the last piece of code in a commandlinerunner inside the primary class of the application and the last choice was a different class with #Component annotation.
My setup is the following: I use a jdbc driver (pgjdbc-ng) to use the listen notify function of postgres.I have a function and a trigger that listens to a specific postgres table for inserations. If any occur, notifications are sent through the websocket. The other and is an angular app that uses ng2-stompjs to listen to /topic/notificari for notifications. I am not posting the code because the notifications don't get out of spring, the angular is not the problem.
Kind regards,
This is my WebSocketConfiguration
Override
public void configureMessageBroker(MessageBrokerRegistry registry) {
registry.enableSimpleBroker("/topic", "/queue", "/user", "/notificari");
registry.setApplicationDestinationPrefixes("/app");
registry.setUserDestinationPrefix("/user");
}
#Override
public void registerStompEndpoints(StompEndpointRegistry registry) {
registry.addEndpoint("/socket").setAllowedOrigins("*")
.setHandshakeHandler(new CustomHandshakeHandler());
}
I am using a class ListenNotify and the JDBC driver pgjdbc-ng to connect to the postgresql db and use listen notify functionality
public class ListenNotify {
private BlockingQueue queue = new ArrayBlockingQueue(20);
PGConnection connection;
public ListenNotify() {
PGNotificationListener listener = new PGNotificationListener() {
#Override
public void notification(int processId, String channelName, String payload) {
queue.add(payload);
}
};
try {
PGDataSource dataSource = new PGDataSource();
dataSource.setHost("localhost");
dataSource.setDatabase("db");
dataSource.setPort(5432);
dataSource.setUser("user");
dataSource.setPassword("pass");
connection = (PGConnection) dataSource.getConnection();
connection.addNotificationListener(listener);
Statement statement = connection.createStatement();
statement.execute("LISTEN n_event");
statement.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
public BlockingQueue getQueue() {
return queue;
}
}
And finally this is the code that instantiate the ListenNotify object and listens to postgres for events that might trigger notifications that have to be send using websocket.
#Component
public class InstantaNotificari {
#Autowired
SimpMessagingTemplate template;
#EventListener(ApplicationReadyEvent.class)
public void runn() {
System.out.println("invocare met");
ListenNotify ln = new ListenNotify();
BlockingQueue queue = ln.getQueue();
System.out.println("the que ies "+ queue);
while (true) {
try {
String msg = (String) queue.take();
System.out.println("msg " + msg);
template.convertAndSend("/topic/notificari", msg);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
I didn't use Spring so I can't test your code. Here is my tested version. I think this summarizes the differences -
Change to a try with resources block. This will close the connection on destruction of the class.
Move your while(true) into the try block on the Listener so that the
lines inside the try block doesn't ever get out of execution scope.
The while(true) is blocking, so it needs to be on another thread. ListenNotify extends Thread
I'm sure there are other ways of implementing and welcome corrections to any of my assumptions.
My tested, running code is in this answer JMS Websocket delayed delivery.
On GWTP I am sending a UpdateDiagramBoxEvent with the code below, but the handler is executed twice. In other words, I can see that the sendUpdateDiagramBoxEvent() is executed only once, but it is received twice. The same is happening with many other events on my code. Any ideas of what is wrong, and how can I avoid this behaviour? THANKS.
Receive event
UpdateDiagramBoxHandler updateDiagramBoxHandler = new UpdateDiagramBoxHandler() {
#Override
public void onUpdateDiagramBox(UpdateDiagramBoxEvent event) {
doSomething();
}
};
Send event
EventUtil.sendUpdateDiagramBoxEvent(CellTableManager.this.eventBus,
BasicConstants.EventSubscriptors.VIEW, 0,
BasicConstants.EditableTableFields.DIAGRAMTYPE,
ClientState.getCurrentDiagramType().name());
public static void sendUpdateDiagramBoxEvent(final EventBus eventBus,
final BasicConstants.EventSubscriptors recipient,
final int index, final BasicConstants.EditableTableFields field,
final String value){
Scheduler.get().scheduleDeferred(new ScheduledCommand() {
#Override
public void execute() {
UpdateDiagramBoxEvent updateDiagramBoxEvent =
new UpdateDiagramBoxEvent(transactionNumber, recipient,
field.toString(), value, index);
eventBus.fireEvent(updateDiagramBoxEvent);
}
});
}
Register event handler (from MyProjectPresenter.java)
#Inject PlaceManager placeManager;
#Override
protected void onBind() {
[...]
registerHandler(getEventBus().addHandler(UpdateDiagramBoxEvent.getType(),
updateDiagramBoxHandler));
}
It generally means that you simply registered your event handlers twice.
Is this GWTP and if so how are you registering your events/handlers? I seem to recall there is a pitfall that you can use either #ProxyEvent or addRegisteredHandler() but not both, or you will receive the events twice.
Hope that helps.
Cheers,
Or the bean in question might not be singleton.
I'm trying to unit test the custom events that I've created in Spring and am running into an interesting problem. If I create a StaticApplicationContext and manually register and wire the beans I can trigger events and see the program flow through the publisher (implements ApplicationEventPublisherAware) through to the listener (implements ApplicationListener<?>).
Yet when I try to create a JUnit test to create the context using the SpringJunit4ClassRunner and #ContextConfiguration everything works well except that the ApplicationEvents are not showing up in the listener (I have confirmed that they are getting published).
Is there some other way to create the context so that ApplicationEvents will work correctly? I haven't found much on the web about unit testing the Spring events framework.
The events will not fire because your test classes are not registered and resolved from the spring application context, which is the event publisher.
I've implemented a workaround for this where the event is handled in another class that is registered with Spring as a bean and resolved as part of the test. It isn't pretty, but after wasting the best part of a day trying to find a better solution I am happy with this for now.
My use case was firing an event when a message is received within a RabbitMQ consumer. It is made up of the following:
The wrapper class
Note the Init() function that is called from the test to pass in the callback function after resolving from the container within the test
public class TestEventListenerWrapper {
CountDownLatch countDownLatch;
TestEventWrapperCallbackFunction testEventWrapperCallbackFunction;
public TestEventListenerWrapper(){
}
public void Init(CountDownLatch countDownLatch, TestEventWrapperCallbackFunction testEventWrapperCallbackFunction){
this.countDownLatch = countDownLatch;
this.testEventWrapperCallbackFunction = testEventWrapperCallbackFunction;
}
#EventListener
public void onApplicationEvent(MyEventType1 event) {
testEventWrapperCallbackFunction.CallbackOnEventFired(event);
countDownLatch.countDown();
}
#EventListener
public void onApplicationEvent(MyEventType2 event) {
testEventWrapperCallbackFunction.CallbackOnEventFired(event);
countDownLatch.countDown();
}
#EventListener
public void onApplicationEvent(OnQueueMessageReceived event) {
testEventWrapperCallbackFunction.CallbackOnEventFired(event);
countDownLatch.countDown();
}
}
The callback interface
public interface TestEventWrapperCallbackFunction {
void CallbackOnEventFired(ApplicationEvent event);
}
A test configuration class to define the bean which is referenced in the unit test. Before this is useful, it will need to be resolved from the applicationContext and initialsed (see next step)
#Configuration
public class TestContextConfiguration {
#Lazy
#Bean(name="testEventListenerWrapper")
public TestEventListenerWrapper testEventListenerWrapper(){
return new TestEventListenerWrapper();
}
}
Finally, the unit test itself that resolves the bean from the applicationContext and calls the Init() function to pass assertion criteria (this assumes you have registered the bean as a singleton - the default for the Spring applicationContext). The callback function is defined here and also passed to Init().
#ContextConfiguration(classes= {TestContextConfiguration.class,
//..., - other config classes
//..., - other config classes
})
public class QueueListenerUnitTests
extends AbstractTestNGSpringContextTests {
private MessageProcessorManager mockedMessageProcessorManager;
private ChannelAwareMessageListener queueListener;
private OnQueueMessageReceived currentEvent;
#BeforeTest
public void Startup() throws Exception {
this.springTestContextPrepareTestInstance();
queueListener = new QueueListenerImpl(mockedMessageProcessorManager);
((QueueListenerImpl) queueListener).setApplicationEventPublisher(this.applicationContext);
currentEvent = null;
}
#Test
public void HandleMessageReceived_QueueMessageReceivedEventFires_WhenValidMessageIsReceived() throws Exception {
//Arrange
//Other arrange logic
Channel mockedRabbitmqChannel = CreateMockRabbitmqChannel();
CountDownLatch countDownLatch = new CountDownLatch(1);
TestEventWrapperCallbackFunction testEventWrapperCallbackFunction = (ev) -> CallbackOnEventFired(ev);
TestEventListenerWrapper testEventListenerWrapper = (TestEventListenerWrapper)applicationContext.getBean("testEventWrapperOnQueueMessageReceived");
testEventListenerWrapper.Init(countDownLatch, testEventWrapperCallbackFunction);
//Act
queueListener.onMessage(message, mockedRabbitmqChannel);
long awaitTimeoutInMs = 1000;
countDownLatch.await(awaitTimeoutInMs, TimeUnit.MILLISECONDS);
//Assert - assertion goes here
}
//The callback function that passes the event back here so it can be made available to the tests for assertion
private void CallbackOnEventFired(ApplicationEvent event){
currentEvent = (OnQueueMessageReceived)event;
}
}
EDIT 1: The sample code has been updated with CountDownLatch
EDIT 2: Assertions didn't fail tests so the above was updated with a different approach**
I just run my app as SpringBootTest, application events working fine:
#TestComponent
public class EventTestListener {
#EventListener
public void handle(MyCustomEvent event) {
// nothing to do, just spy the method...
}
}
#RunWith(SpringRunner.class)
#SpringBootTest
public class MyEventTest {
#SpyBean
private EventTestListener testEventListener;
#Test
public void testMyEventFires() {
// do something that fires the event..
verify(testEventListener).handle(any(MyCustomEvent.class));
}
}
use the #Captor / ArgumentCaptor to verify the content of your event.
You can create a context manually.
For example: I had needed to check if my ApplicationListener<ContextClosedEvent> closed Cassandra connections:
#Test
public void testSpringShutdownHookForCassandra(){
ConfigurableApplicationContext ctx = new AnnotationConfigApplicationContext(CassandraConfig.class);
CassandraConnectionManager connectionManager = ctx.getBean(CassandraConnectionManager.class);
Session session = connectionManager.openSession(testKeySpaceName);
Assert.assertFalse( session.isClosed() );
ctx.close();
Assert.assertTrue( session.isClosed() );
}
In order to use events only listened if a transaction succeeds or fails, I'm following the given doc about transactional observers :
http://docs.jboss.org/weld/reference/1.1.0.Final/en-US/html_single/#d0e4075
... but cannot manage to make my code work on JBoss AS7.
Here's my EJB:
#LocalBean
#Stateful
#TransactionAttribute(TransactionAttributeType.NEVER)
public class MyController
{
#Inject
private transient Event<MyEvent> myEventLauncher;
#TransactionAttribute(TransactionAttributeType.REQUIRES_NEW)
public void save()
{
myEventLauncher.fire(new MyEvent());
}
#AfterCompletion
protected void afterSave(boolean isCommitted)
{
// do stuff
}
}
And here my basic listener:
public class MyHandler
{
protected void listenMyEvent(#Observes(during=TransactionPhase.AFTER_SUCCESS) MyEvent event)
{
// do stuff
}
protected void listenMyEvent2(#Observes(during=TransactionPhase.AFTER_FAILURE) MyEvent event)
{
// do stuff
}
}
I can say I'm in a transaction when the event is fired, because the afterSave method of the EJB is called. Alas, the methods listenMyEvent and listenMyEvent2 are always called both, like if I was not in a transactional context.
I tried the same code on GlassFish 3 and it perfectly works, so I guess there is a problem with JBoss AS 7, but I cannot find any bug report about it.
Well, as my current tests made me think that transactional observers are not working in JBoss AS 7, I managed to do a workaround I gave here for people who are interested.
First, we need qualifier annotations: Immediate, AfterFailure and AfterSuccess.
#Qualifier
#Retention(RetentionPolicy.RUNTIME)
#Target({ ElementType.FIELD, ElementType.PARAMETER })
public #interface AfterFailure
{}
#Qualifier
#Retention(RetentionPolicy.RUNTIME)
#Target({ ElementType.FIELD, ElementType.PARAMETER })
public #interface AfterSuccess
{}
#Qualifier
#Retention(RetentionPolicy.RUNTIME)
#Target({ ElementType.FIELD, ElementType.PARAMETER })
public #interface Immediate
{}
Also, three basic AnnotationLiteral to create in runtime instances of this three annotations.
Then, we need a encapsulator for our true events, that I named SpecialEvent.
public class SpecialEvent
{
private Object event; // the real event you want
public SpecialEvent(Object event)
{
super();
this.event = event;
}
public Object getEvent()
{
return event;
}
}
And at last, an observer for this special event and an interceptor for classes where you want to fire this kind of events (full explanation below).
#RequestScoped
public class SpecialEventObserver
{
#Inject
private Event<Object> anyEventFirer; // firer for real events
private List<Object> events; // queued events
public SpecialEventObserver()
{
events = new ArrayList<Object>();
}
// remove all queued events
public void reset()
{
this.events.clear();
}
public void fireAfterFailureEvents() throws Exception
{
this.fireAllEventsOnce(new AfterFailureLiteral());
}
public void fireAfterSuccessEvents() throws Exception
{
this.fireAllEventsOnce(new AfterSuccessLiteral());
}
protected void listenSpecialEvent(#Observes SpecialEvent specialEvent)
{
Object event = specialEvent.getEvent();
this.events.add(event);
this.fireEvent(event, new ImmediateLiteral());
}
protected void fireAllEventsOnce(Annotation qualifier) throws Exception
{
try
{
for (Object event : this.events)
{
this.fireEvent(event, qualifier);
}
}
catch (Exception e)
{
throw e;
}
finally
{
this.events.clear();
}
}
protected void fireEvent(Object event, Annotation qualifier)
{
Event eventFirer = anyEventFirer.select(event.getClass(), qualifier);
eventFirer.fire(event);
}
}
#Interceptor
#LocalInterception
public class MyInterceptor implements Serializable
{
#Inject
private SpecialEventObserver specialEventObserver;
#AroundInvoke
public Object intercept(InvocationContext ic) throws Exception
{
specialEventObserver.reset();
try
{
// call the real method
Object proceedResult = ic.proceed();
// real method succeeded, fire successful events
specialEventObserver.fireAfterSuccessEvents();
return proceedResult;
}
catch (Exception e)
{
// real method failed, fire failed events
specialEventObserver.fireAfterFailureEvents();
throw e;
}
}
}
The mechanism is quite simple:
When you want to fire an event, fire a SpecialEvent that hold the true event.
The SpecialEventObserver will catch any SpecialEvent and will immediately fire your own event with an Immediate qualifier. It will also queue the events for the after completion part.
At the end of your own method call (ic.proceed in the interceptor), MyInterceptor will ask the SpecialEventObserver either to fire again all events with a AfterFailure qualifier or a AfterSuccess qualifier, depending of the success of your method.
In place of #Observes(during=...), your own observers have to observe events with the right qualifier, like #Observes #Immediate, #Observes #AfterFailure or #Observes #AfterSuccess.
The behavior is not exactly the one that provides the native #Observes(during=...). The after completion part is not based on the transaction state, but on your own method call success:
In JaveEE6, transactional observers on after success or after failure phases must be immediately called if you're not in a transaction, like a IN_PROGRESS would do.
In this workaround, observers on after success or after failure phases will always be called at the end of the method, and only if it succeeded or failed.
This works with version 7.1.0.Final which is supposedly (-> with Jboss you never know) fully Java EE compliant. Also your bean is not thread-safe as it uses list instead of a concurrent queue.
Your observer methods need REQUIRES_NEW, as stated here :
http://www.seamframework.org/Documentation/WhyIsThereNoActiveTransactionInMySFSBTransactionalObserver