I'm using Apache Camel and Spring (not Spring Boot) with xml.
I have my camel-context.xml configuration file with a sample route from MQTT server to JMS server and viceversa, just to dispatch the messages.
Here is my camel-context.xml:
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:util="http://www.springframework.org/schema/util"
xmlns:camel="http://camel.apache.org/schema/spring"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util.xsd
http://camel.apache.org/schema/spring http://camel.apache.org/schema/spring/camel-spring.xsd">
<bean id="quadtreeProcessor" class="es.gateway.router.QuadtreeProcessor" />
<camelContext id="camelContext" xmlns="http://camel.apache.org/schema/spring">
<route id="quadTreeConsumerProducer">
<from uri="jms:topic:T_ETSI_PRODUCER"/>
<process ref="quadtreeProcessor"/>
<to uri="mqtt:quadtree?host=tcp://localhost:1883&publishTopicName=${header.publishTopicName}"/>
</route>
<route id="quadTreeConsumerRoute">
<from uri="mqtt:quadtree?host=tcp://localhost:1883&subscribeTopicName=CONSUMER/DENM/#"/>
<to uri="jms:topic:T_ETSI_CONSUMER"/>
</route>
</camelContext>
<bean id="jmsConnectionFactory" class="org.apache.activemq.ActiveMQConnectionFactory">
<property name="brokerURL" value="tcp://localhost:10011"/>
</bean>
<bean id="activemq" class="org.apache.activemq.camel.component.ActiveMQComponent" />
And here is my Main.class:
package es.conncar.main;
import org.apache.camel.RuntimeCamelException;
import org.apache.camel.main.MainListener;
import org.apache.camel.main.MainListenerSupport;
import org.apache.camel.main.MainSupport;
import org.apache.log4j.Logger;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import es.gateway.config.Config;
public class Main {
final static Logger logger = Logger.getLogger(Main.class);
private static boolean exit = false;
private org.apache.camel.spring.Main camelMain;
public static void main(String[] args) throws Exception {
try {
ApplicationContext springContext = new ClassPathXmlApplicationContext("app-context.xml");
logger.info("Spring context initialized");
Config config = (Config) springContext.getBean("config");
Main main = new Main();
main.boot();
} catch (Exception e) {
logger.error("Unknown error in main", e);
}
}
public void boot() throws Exception {
camelMain = new org.apache.camel.spring.Main();
camelMain.addMainListener((MainListener) new Events());
camelMain.setApplicationContextUri("camel-context.xml");
logger.info("Starting Camel. Use ctrl + c to terminate the JVM.\n");
camelMain.run();
}
public static class Events extends MainListenerSupport {
@Override
public void afterStart(MainSupport main) {
logger.info("Camel is now started!");
}
@Override
public void beforeStop(MainSupport main) {
logger.info("Camel is now being stopped!");
}
}
}
The problem ocurrs when running the same route and configuration within my Main class, which dies after a few seconds because of a RuntimeCamelException.
The exception trace is:
Camels starts ok
[30/11/2018 08:37:08][INFO ][es.gateway.main.Main] - Spring context initialized
[30/11/2018 08:37:08][INFO ][es.gateway.main.Main] - Starting Camel. Use ctrl + c to terminate the JVM.
After 10 seconds
[30/11/2018 08:37:21][ERROR][es.gateway.main.Main] - Unknown error in Camel
org.apache.camel.RuntimeCamelException: java.util.concurrent.TimeoutException
at org.apache.camel.util.ObjectHelper.wrapRuntimeCamelException(ObjectHelper.java:1830)
at org.apache.camel.spring.SpringCamelContext.start(SpringCamelContext.java:136)
at org.apache.camel.spring.CamelContextFactoryBean.start(CamelContextFactoryBean.java:369)
at org.apache.camel.spring.CamelContextFactoryBean.onApplicationEvent(CamelContextFactoryBean.java:416)
at org.apache.camel.spring.CamelContextFactoryBean.onApplicationEvent(CamelContextFactoryBean.java:94)
at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172)
at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165)
at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139)
at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:393)
at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:347)
at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:883)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:546)
at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139)
at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:93)
at org.apache.camel.spring.Main.createDefaultApplicationContext(Main.java:222)
at org.apache.camel.spring.Main.doStart(Main.java:154)
at org.apache.camel.support.ServiceSupport.start(ServiceSupport.java:61)
at org.apache.camel.main.MainSupport.run(MainSupport.java:170)
at es.gateway.main.Main.boot(Main.java:105)
at es.gateway.main.Main.main(Main.java:77)
Caused by: java.util.concurrent.TimeoutException
at org.fusesource.mqtt.client.Promise.await(Promise.java:83)
at org.apache.camel.component.mqtt.MQTTEndpoint.connect(MQTTEndpoint.java:348)
at org.apache.camel.component.mqtt.MQTTConsumer.doStart(MQTTConsumer.java:38)
at org.apache.camel.support.ServiceSupport.start(ServiceSupport.java:61)
at org.apache.camel.impl.DefaultCamelContext.startService(DefaultCamelContext.java:3705)
at org.apache.camel.impl.DefaultCamelContext.doStartOrResumeRouteConsumers(DefaultCamelContext.java:4023)
at org.apache.camel.impl.DefaultCamelContext.doStartRouteConsumers(DefaultCamelContext.java:3958)
at org.apache.camel.impl.DefaultCamelContext.safelyStartRouteServices(DefaultCamelContext.java:3878)
at org.apache.camel.impl.DefaultCamelContext.doStartOrResumeRoutes(DefaultCamelContext.java:3642)
at org.apache.camel.impl.DefaultCamelContext.doStartCamel(DefaultCamelContext.java:3494)
at org.apache.camel.impl.DefaultCamelContext.access$000(DefaultCamelContext.java:209)
at org.apache.camel.impl.DefaultCamelContext$2.call(DefaultCamelContext.java:3253)
at org.apache.camel.impl.DefaultCamelContext$2.call(DefaultCamelContext.java:3249)
at org.apache.camel.impl.DefaultCamelContext.doWithDefinedClassLoader(DefaultCamelContext.java:3272)
at org.apache.camel.impl.DefaultCamelContext.doStart(DefaultCamelContext.java:3249)
at org.apache.camel.support.ServiceSupport.start(ServiceSupport.java:61)
at org.apache.camel.impl.DefaultCamelContext.start(DefaultCamelContext.java:3165)
at org.apache.camel.spring.SpringCamelContext.start(SpringCamelContext.java:133)
... 18 more
It looks like the route throws a timeout when not able to connect to the MQTT broker (that's ok) but this exception is not caught within the route but in the context - Main class (that's not ok).
I've followed this cookbook:
http://camel.apache.org/running-camel-standalone-and-have-it-keep-running.html
with camel-spring JAR in the org.apache.camel.spring.Main class.
I also checked the chapter 13 in the book Apache Camel in Action but I did not find a solution to this. It seems I'm starting and configuring camel context just fine.
Anybody has experience this? Is there a way to keep routes working and Main programm alive when RuntimeExceptions ocurrs in the routes? I hope so!
Thansk in advance!
EDIT: I have found several topics talking about this. The solution seems to be activating the Supervising Controller, but I can't find a way to do it without Spring Boot (I'm using plain Spring with mixed xml and annotations config). Anybody could help?
How to start camel even if the MQTT server is not reachable
Spring Context shutting down camel routes when activemq connection is lost
EDIT2: I have checked that the problem is only with MQTT. The JMS connection works correctly and is able to go on even when JMS broker is down and handle handle reconnections gracefully, while the MQTT connection not.
EDIT3: Paho works fine but plain MQTT not. I've tested the same code with Paho in xml config (uri) and it behaves as expected, similar to JMS. The route throws exceptions but keep going, it doesn't raise the exception to the context which is what causes the application to stop. Maybe I'm missing options in the MQTT client?
onexceptionXML dsl structure and set handled to true. – Namphibian