A content-based router, shown in Figure 21, enables you to route messages to the appropriate destination based on the message contents.

Figure 21. Content-Based Router Pattern

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

RouteBuilder builder = new RouteBuilder() {
    public void configure() {
        from("seda:a").choice()
          .when(header("foo").isEqualTo("bar")).to("seda:b")
          .when(header("foo").isEqualTo("cheese")).to("seda:c")
          .otherwise().to("seda:d");
    }
};

The following example shows how to configure the same route in XML:

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