Apache Camel parallel Split - knowing when work has finished? - apache-camel

Question

I'm struggling with a use case we have to split a message, send the split messages to a JMS queue and then do something when all the split items from that first message have been processed on the queue.
I'm aware that I could use parallelProcessing on the split, but for reasons it would be tedious to go into that's not possible in this case.
I've got JMS sending replyTo messages to a queue. Is there any way to make the end() after a split().to("jms:aqueuethatreplies") block until all replies for that split have been received?
Here's some example code - I'd like the "Completed:" message only to be printed when I've already seen all the appropriate "Item received:" messages.
import org.apache.activemq.ActiveMQConnectionFactory;
import org.apache.camel.*;
import org.apache.camel.builder.RouteBuilder;
import org.apache.camel.component.jms.JmsComponent;
import org.apache.camel.impl.DefaultCamelContext;
import javax.jms.ConnectionFactory;
import java.util.Random;
public class SplitAndAggregate {
public static void main(String args[]) throws Exception {
CamelContext context = new DefaultCamelContext();
ConnectionFactory connectionFactory =
new ActiveMQConnectionFactory("vm://localhost?broker.persistent=false");
context.addComponent("jms",
JmsComponent.jmsComponentAutoAcknowledge(connectionFactory));
// add our route to the CamelContext
context.addRoutes(new RouteBuilder() {
#Override
public void configure() {
from("direct:somexml")
.split(xpath("/items/item"))
.to("jms:item")
.end()
.process(new Processor() {
#Override
public void process(Exchange exchange) throws Exception {
System.out.println("Completed:" + System.lineSeparator() + toStr(exchange));
}
})
.end();
from("jms:item?maxConcurrentConsumers=10&exchangePattern=InOut&replyTo=replyqueue")
.process(new Processor() {
public void process(Exchange exchange) throws Exception {
sleep();
System.out.println("Item received:" + System.lineSeparator() + toStr(exchange));
}
});
}
});
ProducerTemplate producerTemplate = context.createProducerTemplate();
context.start();
producerTemplate.sendBody("direct:somexml",
"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n" +
"<items>\n" +
" <item>item1</item>\n" +
" <item>item2</item>\n" +
" <item>item3</item>\n" +
"</items>\n");
producerTemplate.sendBody("direct:somexml",
"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n" +
"<items>\n" +
" <item>item4</item>\n" +
" <item>item5</item>\n" +
" <item>item6</item>\n" +
"</items>\n");
Thread.sleep(10000);
context.stop();
}
private static String toStr(Exchange exchange) {
if (exchange != null) {
return "In:"+System.lineSeparator()+toStr(exchange.getIn())+"Out:"+System.lineSeparator()+toStr(exchange.getOut());
} else {
return "null";
}
}
private static String toStr(Message message) {
if (message != null) {
return message.getHeaders() + System.lineSeparator() + message.getBody()+System.lineSeparator();
} else {
return "null";
}
}
public static void sleep() throws InterruptedException {
Thread.sleep(new Random().nextInt(1000));
}
}