Camel: communicating between two routes - apache-camel

I'm basically new to camel. I set up a camel context with two routes that are using seda endpoints.
Simplyfying, all starts with a "from" file endpoint (sorry for the terminology if wrong) listening on a directory:
<route>
<from uri="file:mydir"/>
<process ref="a bean that change the body of the message by setting a custom object"/>
<to uri="seda:incoming"/>
</route>
<route>
<from uri="seda:incoming"/>
<process ref="a bean that does something with the custom object above"/>
....
</route>
now, what described above works perfectly but i need to change seda with activemq queues and after doing that the body of the message received by the 2nd processor is empty.
How can I obtain the same behaviour of seda endpoints using activemq channels?

exchange.getIn().setBody(myCustomBean)
and
exchange.getIn().setHeader("inputfile", aFileInstance)
If you expect to get some result when aquiring from activemq queue, you should send serializable object to queue. Otherwise object will not be transferred.
At your case there's no guarantee that myCustomBean and aFileInstance are serializable.
Basically try sending the Strings into the queue. Or make your objects serializable.

Related

Apache Camel AMQP with selector is consuming any message

I am trying to use selectors on an amqp with Azure Service Bus consumer. However, for some reason the route is also consuming messages that do not match the selector.
Here's an example:
This route generates messages and append a header:
<route id="MessageGenerator">
<from uri="timer:generator?delay=5000&period=5000"/>
<setHeader headerName="INSTANCE_ID">
<simple>{{env:INSTANCE_ID}}</simple>
</setHeader>
<to uri="amqp:queue:external_queue" />
</route>
While this route should consume only those that contain INSTANCE_ID matching 2 possible values: env:INSTANCE_ID or Any.
<route id="ExternalConsumer">
<from uri="amqp:queue:external_queue?selector=INSTANCE_ID IN ('{{env:INSTANCE_ID}}', 'Any')"/>
<log message="{{env:INSTANCE_ID}} consumed message with Instance ID: ${header.INSTANCE_ID}" logName="AMQP_TEST" loggingLevel="INFO"/>
</route>
But the the log shows that it is consuming any message, regardless of the selector specifying which ones.
Am I missing something?
Thanks!
Issue here was that Azure Service Bus does NOT support selectors on queues. I switched to topics, which already have filters per subscription.

How to filter jms message in apache camel xml configuration file

I wish to create jms subscriber on a general topic. to avoid unwanted messages i wish to create a filter there. the problem is the syntax is available every where from java code but I can not find how to do same in xml configuration file like blueprint.xml
Java code
String redSelector = "color='red'";
MessageConsumer redConsumer = redSession.createConsumer(queue, redSelector);
Apache camel route
<route id="externalNotificationsDispatchRoute" >
<from uri="activemq:queue:{{vqueue.name}}" />
.. filtering part
<to uri="log:com?level=DEBUG" />
</route>
JMS Message Selector is specified with selector URI parameter.
Blueprint:
<from uri="activemq:queue:{{vqueue.name}}?selector={{vqueue.selector}}" />
Property file:
vqueue.selector=color%3D'red'
Refer JMS component documentation (ActiveMQ component iherits the parameters from the JMS component)
selector
Sets the JMS Selector, which is an SQL 92 predicate that is used to filter messages within the broker. You may have to encode special characters like '=' as %3D.

Camel-http httpclient timeout from exchange headers

I have a http component in my route in which I want to pass timeout value from exchange header's.
http://foo.com?httpClient.soTimeout=5000
How can we do this in Spring DSL.
Is is possible to do something like:
<to uri="http://foo.com?httpClient.soTimeout=${in.headers.timeout}"/>
Unfortunately, no, <to> DSL will create the endpoint and the producer before any exchange is received and for HTTP component SO_TIMEOUT is not a parameter that you can change in runtime (here's a list of what you can change).
That being said, if you are using Camel 2.16+ you can easily do it with Dynamic To endpoint. In your case that would be:
<toD uri="http://foo.com?httpClient.soTimeout=${in.headers.timeout}"/>
Otherwise, you'll have to use the Dynamic Recipient List EIP:
<setHeader headerName="theHeader">
<simple>http://foo.com?httpClient.soTimeout=${in.headers.timeout}</simple>
</setHeader>
<recipientList>
<header>theHeader</header>
</recipientList>

Apache Camel Exchange to Propagate from one process to another

I am looking out for a way by which in Apache Camel, I can stop a exchange to propagate from one process to another, without stoping and restarting the route itself. I had below route configured and what I am basically looking out is to return the exchange from messageMultiplierProcessor based on some conditions without changing/modifying the exchange body or setting/resetting it headers.
<route id="business-logic-route">
<from uri="direct:business-logic-endpoint"/>
<setProperty propertyName="esq.route.name">
<constant>TestRoute</constant>
</setProperty>
<process ref="messageMultiplierProcessor" />
<process ref="calculatedFieldsProcessor" />
You can conditionally stop a route at any point using "when" & "stop":
<when>some condition</when>
<stop/>

Exchange id in camel request ends with even number

I am using Apache Camel in OSGI scenario using Karaf in version 2.15.1. I am using the exchange.getExchangeId() to print the exchange id in a request/reply. The exchange pattern is set to InOnly. The route looks like this:
<route id="ip_client_rpc">
<from uri="restlet:http://localhost:7070/lsp/patron/id?restletMethod=POST&synchronous=true"/>
<to uri="log:${headers}"/>
<setExchangePattern pattern="InOnly"/>
<process ref="rabbit_client"/>
<to uri="log:${headers}"/>
</route>
However when I print the exchange id sent to the rabbitmq queue it always ends with an even number.
Request from client:ID-VirtualDev-49301-1443430754519-5-6
Request from client:ID-VirtualDev-49301-1443430754519-5-8
Request from client:ID-VirtualDev-49301-1443430754519-5-10
Request from client:ID-VirtualDev-49301-1443430754519-5-12
Request from client:ID-VirtualDev-49301-1443430754519-5-14
Is there a reason why the final digit is always even? Is there another exchange being created that I am missing?
Thanks
Camel uses the same id generator for generating unique ids for different things, its just by chance that its even in this case. Could be that a breadcrumb or message id was also generated that takes the odd number.

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