Read MQTT topic of received message in Camel Route - apache-camel

I am trying to configure an Apache Camel Spring Route. I would like to consume messages from MQTT and print them with their topic. How do I get the topic the message was published to?
I'm using Apache Camel 2.16.1
My camel-context.xml
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://camel.apache.org/schema/spring http://camel.apache.org/schema/spring/camel-spring.xsd">
<camelContext xmlns="http://camel.apache.org/schema/spring" id="MqttCamel">
<route>
<from uri="mqtt:iot?host=tcp://iot.eclipse.org:1883&subscribeTopicNames=#" />
<convertBodyTo type="java.lang.String" />
<to uri="stream:out" />
</route>
</camelContext>
</beans>

With the MQTT component, the topic is stored in a header called "CamelMQTTSubscribeTopic":
from("mqtt:foo?subscribeTopicName=#&host=tcp://127.0.0.1:1883")
.log("Message read from topic ${in.header.CamelMQTTSubscribeTopic}.");

If saying Apache Paho they use CamelMqttTopic header name. And it's possible to use
${in.header.CamelMqttTopic}
and
${header.CamelMqttTopic}
So this
from("paho:#")
.log("Message read from topic ${in.header.CamelMqttTopic}.")
.log("Message read from topic ${header.CamelMqttTopic}.")
.bean(mqttService, "received(${header.CamelMqttTopic}, ${body})")
;
works.
received method is
public void received(String topic, String payload) {
log.info("topic: {}", topic);
log.info("payload: {}", payload);
}
And i got to my log:
Message read from topic my/topic/name.
Message read from topic my/topic/name.
topic: my/topic/name
payload: payload message
See here https://cwiki.apache.org/confluence/display/CAMEL/Paho
Tested on Paho 2.25.1

Related

Limit netty4 tcp endpoint to a single instance

I have a mock endpoint at 8001 that will echo anything provided to it.
I have an http endpoint that will submit the end of the URL to the mock endpoint, and provide a response from the endpoint's response.
That works fine.
The challenge is, I want the http route to use only 1 tcp connection to the 8001 endpoint.
I created a worker group as explained elsewhere, and set the worker count to 1. Looking through the source code, I'm thinking this approach should work.
However, when I do this bash command:
for a in {1..5}; do curl "http://localhost:8080/upstream/REQUESTNUM$a" > $a.txt & done;
I see multiple connections to 8001. I would have expected the http endpoint requests would have to share a single pool worker, but that doesn't seem to be the case.
Perhaps I am missing something, or perhaps there is another way to accomplish my goal of using only 1 back-end tcp connection for all the http requests.
How do I accomplish it?
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://camel.apache.org/schema/spring http://camel.apache.org/schema/spring/camel-spring.xsd">
<camelContext
xmlns="http://camel.apache.org/schema/spring">
<route id="mockUpstream">
<from
uri="netty4:tcp://localhost:8001?sync=true&textline=true&keepAlive=true&disconnect=false&reuseChannel=true" />
<log message="Incoming to upstream: ${body}" />
<transform>
<simple>${body}</simple>
</transform>
</route>
<route id="httpServer">
<from
uri="netty4-http:http://0.0.0.0:8080/upstream?matchOnUriPrefix=true" />
<!-- optional just use CamelHttpQuery from header, for full query -->
<log
message="Incoming http command: ${in.headers[CamelHttpPath]}" />
<transform>
<simple>${in.headers[CamelHttpPath]}</simple>
</transform>
<to
uri="netty4:tcp://localhost:8001?workerGroup=#sharedPool&sync=true&textline=true&keepAlive=true&disconnect=false&reuseChannel=true" />
<transform>
<simple>${body}</simple>
</transform>
</route>
</camelContext>
<bean id="poolBuilder"
class="org.apache.camel.component.netty4.NettyWorkerPoolBuilder">
<property name="workerCount" value="1" />
</bean>
<bean id="sharedPool" class="io.netty.channel.EventLoopGroup"
factory-bean="poolBuilder" factory-method="build"
destroy-method="shutdown">
</bean>
</beans>
Looking at the logs, with TRACE level logging, I saw the NettyProducer's pool was indeed set to use 1 max active connection, but the NettyProducer was allowed 100 idle connections. I changed the following line and it is now behaving as expected:
<to
uri="netty4:tcp://localhost:8001?workerGroup=#sharedPool&sync=true&textline=true&keepAlive=true&disconnect=false&reuseChannel=true&producerPoolMaxActive=1&producerPoolMaxIdle=1" />
I assumed the "producer" settings were only good for the producer side (netty in mock host route) of the connection, but it looks like they can be used by the consumer end (netty in http route), too.
edit: I confused the terms producer and consumer and got that backwards above. Seeing that the "to" element is producing a request for something to consume, the producer* parameters make sense for (netty in http route). The (netty in mock host route) is the consumer of requests.

Camel and Spring Integration

I want to test camel spring integration example from the apache camel site
http://camel.apache.org/springintegration.html but I am getting the exception
org.apache.camel.RuntimeCamelException: org.springframework.integration.MessageDeliveryException: Dispatcher has no subscribers for channel outputchannel.
my short code is given below:
<channel id="inChannel"/>
<channel id="outputChannel"/>
<beans:bean id="greeting" class="com.javarticles.spring.integration.Greeting"/>
<service-activator input-channel="inChannel" ref="greeting" method="sayHello" output-channel="outputChannel"/>
<camelContext id="camel" xmlns="http://camel.apache.org/schema/spring">
<route>
<from uri="activemq:activemqsource"/>
<to uri="log:input"/>
<to uri="spring-integration:inChannel? inputChannel=outputChannel"/>
<to uri="log:output"/>
</route>
I tried to search related problems but I did not get with camel could any one tell me how to subscribe the outputchannel
According to the Camel documentation mentioned by you, the config should be like this:
<to uri="spring-integration:inputChannel?inOut=true&inputChannel=outputChannel"/>
Your issue is inOut=true:
The exchange pattern that the Spring integration endpoint should use. If inOut=true then a reply channel is expected, either from the Spring Integration Message header or configured on the endpoint.

set endpoint of an OSGI Blueprint file in ServiceMix

I know I can define Camel routes in stand-alone xml file, using the Blueprint syntax. If I move one of this file in the "deploy" folder of ServiceMix, it automatically becomes an OSGI bundle. My question is, can I set an endpoint to this new bundle, accessible from outside?
I would like to do something like this:
blue_route1.xml
<blueprint>
<camelContext>
<route>
<from uri="http:my_servicemix:8181/blue_route1_endpoint" />
<to uri="jetty:http://server1" />
</route>
</camelContext>
</blueprint>
blue_route1 becomes an OSGI bundle once deployed, but where should I define "blue_route1_endpoint" ? Is it doable?
[UPDATE]
summering, I want that an external WS is able to send messages to blue_route1_endpoint, where the blue_route1 bundle will redirect messages according to Camel routes, without the need to create a new WS "Blue_route1" to deploy in ServiceMix
______________________
| ____________ |
external-->(blue_route1_endpoint)==|==-->|blue_route1|--|-->(http://server1)
WS | |___________| |
|____________________|
ServiceMix
Found it! I didn't get that it's so easy. To make ServiceMix listen on a port, I just have to specify the endpoint using the Camel-jetty component.
So, to answer my question, I solved in this way:
install the camel-jetty component in ServiceMix
features:install camel-jetty
Write the camel-route with Blueprint, in blue_route1.xml file
<?xml version="1.0" encoding="UTF-8"?>
<blueprint
xmlns="http://www.osgi.org/xmlns/blueprint/v1.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="
http://www.osgi.org/xmlns/blueprint/v1.0.0
http://www.osgi.org/xmlns/blueprint/v1.0.0/blueprint.xsd">
<camelContext xmlns="http://camel.apache.org/schema/blueprint">
<route>
<from uri:="jetty:http:my_servicemix:8181/blue_route1_endpoint">
<to uri="http://localhost:8080/user/services/user?bridgeEndpoint=true&throwExceptionOnFailure=false"/>
</route>
<route>
<from uri="jetty:http://0.0.0.0:6969/sp_role?matchOnUriPrefix=true"/>
<setHeader headerName="Content-Type">
<groovy>"text/xml; charset=utf-8"</groovy>
</setHeader>
<to uri="http://server1"/>
</route>
</camelContext>
</blueprint>
I used a random port 8181 to listen to... but I could choose every number, ServiceMix will automatically start a jetty component, listening and consuming on that port/endpoint.
For SOAP messages you need CXF Component and wsdl file of your webservice. You can configure your endpoint outside of the camelContext like this:
<cxf:cxfEndpoint id="yourId" address="/your/address/to/endpoint"
serviceClass="your.java.ServiceClass"
wsdlURL="path/to/your/wsdl/file.wsdl" />
And in your route use tag like this:
<from uri="cxf:bean:yourId"/>
You need to add namespace and schemaLocation to your blueprint to use cxf namespace, use this:
<blueprint xmlns="http://www.osgi.org/xmlns/blueprint/v1.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:cxf="http://camel.apache.org/schema/blueprint/cxf"
xsi:schemaLocation="
http://www.osgi.org/xmlns/blueprint/v1.0.0 http://www.osgi.org/xmlns/blueprint/v1.0.0/blueprint.xsd
http://camel.apache.org/schema/blueprint/cxf http://camel.apache.org/schema/blueprint/cxf/camel-cxf.xsd
http://camel.apache.org/schema/blueprint http://camel.apache.org/schema/blueprint/camel-blueprint.xsd">

messages not being consumed by apache camel using servicemix as a broker

So I'm trying to use apache servicemix/camel to aggregate some messages coming through a JMS queue. The logic I have is dead-simple I just want it to use the last message received and only send it through 3 seconds after the last one.
I have servicemix setup as a message broker and I'm able to use it in such a capacity however it doesn't seem to trigger the route. I've never done this before so odds are I'm horribly off-base but here is what I have so far (put this in deploy/fedora-messaging/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:camel="http://camel.apache.org/schema/spring"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
http://camel.apache.org/schema/spring
http://camel.apache.org/schema/spring/camel-spring.xsd">
<camelContext xmlns="http://camel.apache.org/schema/spring">
<route>
<from uri="activemq:topic:fedora.apim.update.merge"/>
<aggregate completionTimeout="3000">
<correlationExpression>
<simple>header.pid</simple>
</correlationExpression>
<to uri="log:events"/>
<to uri="activemq:topic:fedora.apim.update"/>
</aggregate>
</route>
</camelContext>
<bean id="activemq"
class="org.apache.activemq.camel.component.ActiveMQComponent">
<property name="brokerURL" value="tcp://localhost:61616"/>
</bean>
</beans>
The osgi application appears to start and run without error, and messages are received and queued in the topic:fedora.apim.update.merge however they just sit in the queue and never get consumed or pushed out to the destination queue.
I tested your route as a standalone application (outside of a ServiceMix container) with following broker configuration and everything worked as expected:
<broker xmlns="http://activemq.apache.org/schema/core" useJmx="true"
persistent="false">
<transportConnectors>
<transportConnector uri="tcp://localhost:61616" />
</transportConnectors>
</broker>
So, I guess, we can assume that your Camel route definition is not the problem but the ActiveMQ configuration and/or ServiceMix set-up.
EDIT:
Note, that messages to JMS topic destinations are lost if no active subscriber is connected to the destination. If you need some kind of persistence use durable subscribers or JMS queue destinations.

No declaration for cxfEndpoint in Servicemix deployment

I am trying to get a CXF endpoint working on Servicemix 4. I have created a Spring archetype with a CXF endpoint and successfully installed it with Maven. Having run osgi:install - s mvn: it installs onto Servicemix but the logs are displaying:
Application context refresh failed (OsgiBundleXmlApplicationContext(bundle=springdm,
config=osgibundle:/META-INF/spring/*.xml))
org.springframework.beans.factory.xml.XmlBeanDefinitionStoreException: Line 21 in XML document
from URL [bundle://218.0:0/META-INF/spring/camel-context.xml] is invalid; nested exception is
org.xml.sax.SAXParseException: cvc-complex-type.2.4.c: The matching wildcard is strict, but no
declaration can be found for element 'cxf:cxfEndpoint'
I have built this route just on Camel before with the following in my context.xml file:
<beans ...
xmlns:osgi="http://www.springframework.org/schema/osgi"
xmlns:cxf="http://camel.apache.org/schema/cxf"
xsi:schemaLocation="
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/osgi http://www.springframework.org/schema/osgi/spring-osgi.xsd
http://camel.apache.org/schema/spring http://camel.apache.org/schema/spring/camel-spring.xsd
http://camel.apache.org/schema/cxf http://camel.apache.org/schema/cxf/camel-cxf.xsd
http://cxf.apache.org/tranposrts/camel http://cxf.apache.org/tranposrts/camel.xsd">
<import resource="classpath:META-INF/cxf/cxf.xml" />
<cxf:cxfEndpoint id="wspoc"
address="http://localhost:8181/ws/ping"
serviceClass="net.ja.smx.springdm.PongImpl" />
<camelContext xmlns="http://camel.apache.org/schema/spring">
<route>
<from uri="cxf:bean:wspoc"/>
<to uri="activemq:helloQ" />
</route>
</camelContext>
This is a clone of a working Camel context file but I cannot see why ServiceMix is throwing the error when it starts. The only difference is that the pom file does not use CXF as a dependency but it is in the section which I took from the online example.
I would be grateful for any pointers for any missing imports or corrections to the context file or anything that I ought to check for.
Many thanks.
Shortly after posting, I discovered that I was missing the camel-cxf dependency in my POM file which causes this error. I also needed to make sure that it was the right version as this caused an error in ServiceMix finding the correct META.cxf file.

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