Error handling in Camel Spring DSL

Error handling is one big the major advantage of Camel. It's basically a mimic of the regular try catch finally in the Java language but with more power.The Try Catch Finally as DSL you can use directly on your route.

Sysntax:

<route>

    <from uri="direct:start"/>

    <!-- here the try starts. its a try .. catch .. finally just as regular java code -->

    <doTry>

        <process ref="processorFail"/>

        <to uri="mock:result"/>

        <doCatch>

            <!-- catch multiple exceptions -->

            <exception>java.lang.exception</exception>

            <exception>java.lang.IllegalStateException</exception>

            <to uri="mock:catch"/>

        </doCatch>

        <doFinally>

            <to uri="mock:finally"/>

        </doFinally>

    </doTry>

</route>

Example :


<route id="BLOG_TIMEOUT" >

    <from uri="direct:start"/>

    <!-- here the try starts. its a try .. catch .. finally just as regular java code -->

    <doTry>

       <to uri="{{HTTPURL}}?httpClient.soTimeout=50(Timout in milliseconds)" />

 <to uri="direct:catch"/>

 <!-- catch multiple exceptions -->

        <doCatch>

            <exception>java.net.SocketTimeoutException</exception>

          <handled><constant>true<constant></handled>

            <to uri="direct:catch"/>

        </doCatch>

    <doCatch>

           <exception>java.lang.Exception</exception>

           <handled><constant>true<constant></handled>

            <to uri="direct:catch"/>

        </doCatch>

        <doFinally>

            <to uri="direct:finally"/>

        </doFinally>

    </doTry>

</route>

Above camel route calling one HTTP end point.While returning a response if any error it will fall into catch block and execute the catch endpoint.To simulate rethrowing an exception from a doCatch you should use the handled predicate. If it is evaluated to false Camel will reattach the exception on the Exchange.