I am using doing integration work with Camel and using the HTTP endpoint as a proxy to route certain messages to an HTTP endpoint. I have my route configured to use my custom error handler which places failed messages in a queue that I specified (Dead Letter Channel pattern).
<route>
...
<to uri="direct:MessageTypeGuaranteed"/>
</route>
<route errorHandlerRef="MyCustomErrorHandler">
<from uri="direct:MessageTypeGuaranteed">
<to uri="http://dummyUri?throwExceptionOnFailure=true"/>
</route>
When anything fails to get delivered to my http endpoint, it's being added to my custom queue ("CustomFailedMessageQueue"), and I have a separate route that attempts to retry these messages:
<route>
<from uri="jms:queue:CustomFailedMessageQueue">
<to uri="direct:MessageTypeGuaranteed"/>
</route>
What I'd like to do is to be able to specify that I only want a message to live say for 10 seconds. So I am trying to set time to live on my http destination itself.
For example, I have a processor that does something like this:
exchange.getIn().setHeader(Exchange.HTTP_URI, "http://localhost/nodeserver?timeToLive=10000");
However, I think I have misunderstood the documentation. The timeToLive option is only valid when passing it to the jms component, correct? In other words, if I want to make use of time to live with this end point, I will need to do that handling myself in a processor, correct?
Yes TimeToLive is an option from the JMS spec that the Camel JMS components support. That options has no meaning for other components such as HTTP.
It seems like you may want to use a filter EIP and discard the message if its to old, and you can use a java method etc to implement some code that figures out if its to old or not, and return a boolean
public boolean isNotToOld(Exchange exchange) {
...
return true // to accept and process the message
}
See more about the filter eip here
http://camel.apache.org/message-filter
And you can use it in a route something a like
<from uri="direct:MessageTypeGuaranteed">
<filter>
<method ref="myBean" method="isNotToOld"/>
<to uri="http://dummyUri?throwExceptionOnFailure=true"/>
</filter>
Related
Looks like a weird issue or the docs are missing
Case 1
from("direct:ROUTE1").to("someAPI").to("direct:ROUTE2");
from("direct:ROUTE2").log("${body}"); // BODY is printing
Case 2
from("direct:ROUTE1").to("someAPI").to("direct:ROUTE2").log("${body}");
from("direct:ROUTE2").log("${body}"); // BODY is empty
Does adding log clear the exchange body??
As #Spara and #Claus suggested and to save the hassle on how to enable Stream caching.
Below is the sample code:
Using Java DSL for Single route
from("direct:ROUTER1")
.streamCaching()
.to("direct:ROUTER2");
Using Spring DSL for Single route
<route streamCache="true">
<from uri="direct:ROUTER1"/>
<to uri="direct:ROUTER2"/>
</route>
For global and per route scope using JAVA DSL
context.setStreamCache(true);
from("direct:ROUTER1")
.to("direct:ROUTER2");
For global and per route scope using Spring DSL
<route streamCache="true">
<from uri="direct:ROUTER1"/>
<to uri="direct:ROUTER2"/>
</route>
Note link: Camel Stream Caching
why stream caching
I'm trying to implement the following JMS message flow using camel routes:
there is a topic published on external message broker. My program is listening for messages on this topic. Each incoming message triggers specific route to be executed - ONE TIME ONLY (some kind of ad-hoc, disposable route). This route is supposed to move messages between queues within my internal message broker based on some selector (get all messages from queue A matching given selector and move them to queue B). I'm only starting with camel and so far I figured out just the first part - listening for messages on topic:
<bean id="somebroker" class="org.apache.camel.component.jms.JmsComponent"
p:connectionFactory-ref="rmAdvisoriesConnectionFactory"/>
<camelContext id="camel" xmlns="http://camel.apache.org/schema/spring">
<endpoint id="jms" uri="somebroker:topic:sometopic"/>
<route id="routeAdvisories">
<from ref="jms"/>
<to>???</to>
</route>
</camelContext>
Can you suggest a destination for these advisory messages? I need to read some of their JMS properties and use these values to construct JMS selector that will be used for the "move messages" operation. But I have no idea how to declare and trigger this ad-hoc route. It would be ideal if I could define it within the same camelContext using only Spring DSL. Or alternatively, I could route advisories to some java method, which would be creating and executing this ad-hoc routes. But if this isn't possible, I'll be grateful for any suggestion.
Thanks.
As far as I understand, it will be useful to use the 'selector' option, in your JMS consumer route, for example:
from("activemq:queue:test?selector=key='value1'").to("mock:a");
from("activemq:queue:test?selector=key='value2'").to("mock:b");
Maybe, another option is to implement some routes based on 'Content Based Router Pattern" through "choice" option. You can find more info here: http://camel.apache.org/content-based-router.html
I hope it helps.
I couldn't get it working the way I intended, so I had to abandon my original approach. Instead of using camel routes to move messages between queues (now I'm not sure camel routes are even intended to be used this way) I ended up using ManagedRegionBroker - the way JMX operation "moveMatchingMessagesTo" is implemented - to move messages matching given selector.
I'm trying to setup an Apache Camel route in a Java application where the consumer endpoint is a restlet component that handles an HTTP file upload as a POST of multipart form data and then the producer endpoint forwards the request to a rest service that also accepts multipart form data. I'm new to Camel and can't quite figure out how to wire it up properly. Below is how my route looks so far. Do I need to do any conversion on the body or will the multipart form data be forwarded as is? Can someone provide me some guidance on the proper way to do this or point me to the correct documentation?
<route id="createentityattachment">
<from uri="restlet:/EntityAttachments?restletMethod=POST&restletBinding=#queryStringToHeadersRestletBinding"/>
<camel:recipientList>
<camel:simple>
${header.apigateway}/entityattachments/1.0.0.0/api/v1/EntityAttachments
</camel:simple>
</camel:recipientList>
</route>
I was able to get this working with the below route definition. Note the streamCache="true" attribute on the route. This setting is required for the InputStream to be properly handled in the Exchange. See the Camel docs for more information.
<route id="createentityattachment" streamCache="true">
<from uri="restlet:/EntityAttachments?restletMethod=POST&restletBinding=#queryStringToHeadersRestletBinding"/>
<removeHeaders excludePattern="X-eviCore-EntityAttachments*" pattern="^(Camel|Backbase|User-|Accept|Cache|Cookie|breadcrumbId|Host|Connection|DNT|Upgrade-Insecure-Requests|org.restlet.startTime).*$"/>
<setHeader headerName="CamelHttpMethod">
<constant>POST</constant>
</setHeader>
<to uri="http4://api.innovate.lan:8280/entityattachments/1.0.0.0/api/v1/EntityAttachments"/>
</route>
I have a route that calls an external rest service. I have configured my error handler as shown below.
errorHandler(deadLetterChannel("jms:dlc").maximumRedeliveries(3));
What i want to do:
If connection to external api fails, i want to retry 3 times and then send to deadLetterChannel
If api call is fine, i want to check the status code, log the response and then send the message to deadLetterChannel.
For that i set throwExceptionOnFailure to false.
In my route i have a bean as the last endpoint. This bean receives the response from the external end point and checks for the status.
void process(Exchange exchange){
//check http status code
//if not success
exchange.setProperty(Exchange.ROUTE_STOP,true);
//sendToDeadLetterQueue;
}
My problem is that redelivery happens even when i am able to connect to API. I expect the redelivery to happen on error. But i am handling the response and also setting the exchange to stop.
Can i stop the redelivery from my bean?
You can use onException as follows:
<onException>
<exception>SomeException</exception>
<handled><constant>true</constant></handled>
<process ref="failureResponse"/>
</onException
Use onException tag handled as true
Java DSL
onException(ExceptionClass).handled(true)
.to(deadLetterChannel);
Spring DSL :
<onException>
<exception>SomeException</exception>
<handled><constant>true</constant></handled>
<to uri=deadLetterChannel/>
</onException>
For More Clarification click here
From a logical perspective this is the kind of routing behaviour I wish to implement:
I want to be able to merge the response of an external service with the original request.
I have been able to implement this using multicasting, an aggregator, and a mock endpoint but I was wondering if there is a cleaner way. My current implementation looks like this:
<multicast strategyRef="serviceAggregator" stopOnException="false">
<to uri="mock:foo" />
<to uri="http://0.0.0.0:9999/service/?throwExceptionOnFailure=false" />
</multicast>
<camel:to uri="log:uk.co.company.aggregated?showAll=true" />
<to uri="http://0.0.0.0:9999/anotherService/
The part I particularly don't like is using a mock endpoint but I also don't think that this is a very readable way to express the above diagram. So I was wondering if there was a more elegant way of doing this?
I suggest to read about the EIP patterns, for example the content enricher
http://camel.apache.org/content-enricher.html
Where you can merge the reply message with the request message.
Mind the Content Enricher has 2 modes
- enrich
- pollEnrich
Make sure to notice the difference, from the docs in the link above.
<route>
<from uri="...">
<enrich uri="http://0.0.0.0:9999/service/?throwExceptionOnFailure=false" strategyRef="serviceAggregator"/>
<to uri="log:uk.co.company.aggregated?showAll=true" />
<to uri="http://0.0.0.0:9999/anotherService/>
...
</route>
And yes you diagram is showing splitter, but the sample code is using multicast EIP.
You could simply store the original message in a header or property and later do some merge in a bean. Using the header and the current body.
.setHeader("orig", body())
.to("externalService")
.bean(new MyMergeBean())