Asynchronous Camel Component - doStop() called immediately - apache-camel

Question

I am trying to create a camel component which consumes an API from an external service.
My Route is as follows
from("myComponent:entity?from=&to=")
.to("seda:one")
from("seda:one")
.aggregate(constant(true), new GroupedBodyAggregationStrategy())
.completionSize(5)
.completionTimeout(5000)
.process( new Processor1() )
to("seda:two")
.
.
.
from("seda:five")
.to("myComponent2:entity")
I implemented my component consumer as follows
public class MyComponentConsumer extends DefaultConsumer {
public MyComponentConsumer(MyComponentEndpoint endpoint, Processor processor) {
super(endpoint, processor);
}
#Override
protected void doStart() throws Exception {
super.doStart();
flag = true;
while ( flag ) {
//external API call
Resource resource = getNextResource();
if ( resource.next() == null ) {
flag = false;
}
Exchange ex = endpoint.createExchange(ExchangePattern.InOnly);
ex.getIn().setBody(resource.toString());
getAsyncProcessor().process(
ex
doneSync -> {
LOG.info("Message processed");
}
);
}
}
#Override
protected void doStop() throws Exception {
super.doStop();
System.out.println("stop ---- ");
}
}
Everything worked fine and the data was propogating through the route. My only problem was that data did not propogate to the next part until the whole of this process was completed. And the next parts were running asynchronously.
I looked at the example of StreamConsumer and tried to implement it to my code using a runnable and an executorService. But if I do that consumer stops as soon as it starts.
I changed the code to
public class MyComponentConsumer extends DefaultConsumer implements Runnable
and added
private ExecutorService executor;
getEndpoint().getCamelContext().getExecutorServiceManager().newSingleThreadExecutor(this, "myComponent");
executor.execute(this);
and moved my logic inside the run() method. But, the consumer thread ends as soon as it starts. and the async processor does not transfer the data properly.
Is there any other way to implement the functionality I need or am I mistaken somewhere here. Any help would be appreciated.

Answer 1

What version of camel are you using?
There was an issue with managing the state of consumer in camel 2.x which was fixed in camel 3.x CAMEL-12765 which can lead to the issue you are describing here.
If you are on camel 2.x try using newScheduledThreadPool instead of newSingleThreadExecutor.
Also executor.schedule(this, 5L, TimeUnit.SECONDS) instead of executor.execute(this).
Delayed start of executor might help avoid the problem you are facing.