from("direct:start")
    .routeId("myRoute")
    .choice()
        .when(simple("${header.type} == 'a'"))
            .to("mock:a")
        .when(simple("${header.type} == 'b'"))
            .to("mock:b")
        .otherwise()
            .to("mock:other")
    .end()
    .to("mock:result");