Content Based Router

The Content Based Router from the EIP patterns allows you to route messages to the correct destination based on the contents of the message exchanges.

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The following example shows how to route a request from an input seda:a endpoint to either seda:b, seda:c or seda:d depending on the evaluation of various Predicate expressions

RouteBuilder builder = new RouteBuilder() {
    public void configure() {
        errorHandler(deadLetterChannel("mock:error"));

        from("direct:a")
            .choice()
                .when(header("foo").isEqualTo("bar"))
                    .to("direct:b")
                .when(header("foo").isEqualTo("cheese"))
                    .to("direct:c")
                .otherwise()
                    .to("direct:d");
    }
};

See Why can I not use when or otherwise in a Java Camel route if you have problems with the Java DSL, accepting using when or otherwise.

Using the Spring XML Extensions

<camelContext errorHandlerRef="errorHandler" xmlns="http://camel.apache.org/schema/spring">
    <route>
        <from uri="direct:a"/>
        <choice>
            <when>
                <xpath>$foo = 'bar'</xpath>
                <to uri="direct:b"/>
            </when>
            <when>
                <xpath>$foo = 'cheese'</xpath>
                <to uri="direct:c"/>
            </when>
            <otherwise>
                <to uri="direct:d"/>
            </otherwise>
        </choice>
    </route>
</camelContext>

For further examples of this pattern in use you could look at the junit test case.

Using This Pattern

If you would like to use this EIP Pattern then please read the Getting Started. You may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out.