Defining Camel routes

Camel Quarkus supports several domain specific languages (DSLs) to define Camel Routes.

Java DSL

Extending org.apache.camel.builder.RouteBuilder and using the fluent builder methods available there is the most common way of defining Camel Routes. Here is an example from the timer-log quicksstart:

import org.apache.camel.builder.RouteBuilder;

public class TimerRoute extends RouteBuilder {

    @Override
    public void configure() throws Exception {
        from("timer:foo?period=1000")
                .log("Hello World");
    }
}

Endpoint DSL

Since Camel 3.0, you can use fluent builders also for defining Camel endpoints. The following is equivalent with the previous example:

import org.apache.camel.builder.RouteBuilder;
import static org.apache.camel.builder.endpoint.StaticEndpointBuilders.timer;

public class TimerRoute extends RouteBuilder {

    @Override
    public void configure() throws Exception {
        from(timer("foo").period(1000))
                .log("Hello World");
    }
}

Builder methods for all Camel components are available via camel-quarkus-core, but you still need to add the given component’s extension as a dependency for the route to work properly. In case of the above example, it would be camel-quarkus-timer.

XML DSL

In order to configure Camel routes, rests or templates in XML, you must add a Camel XML parser dependency to the classpath. Since Camel Quarkus 1.8.0, camel-quarkus-xml-io-dsl is the best choice.

With Camel Main, you can set a property that points to the location of resources XML files such as routes, REST DSL and Route templates:

camel.main.routes-include-pattern = routes/routes.xml, file:src/main/routes/rests.xml, file:src/main/rests/route-template.xml

Path globbing like camel.main.routes-include-pattern = *./routes.xml currently does not work in native mode.

Route
<routes xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xmlns="http://camel.apache.org/schema/spring"
        xsi:schemaLocation="
            http://camel.apache.org/schema/spring
            http://camel.apache.org/schema/spring/camel-spring.xsd">

    <route id="xml-route">
        <from uri="timer:from-xml?period=1000"/>
        <log message="Hello XML!"/>
    </route>

</routes>

Spring XML with <beans> or Blueprint XML with <blueprint> elements are not supported.

The route XML should be in the simplified version like:

Rest DSL
<rests xmlns="http://camel.apache.org/schema/spring">
    <rest id="greeting" path="/greeting">
        <get uri="/hello">
            <setBody>
                <constant>Hello World!</constant>
            </setBody>
        </get>
    </rest>
</rests>
Route Templates
<routeTemplates xmlns="http://camel.apache.org/schema/spring">
    <routeTemplate id="myTemplate">
        <templateParameter name="name"/>
        <templateParameter name="greeting"/>
        <templateParameter name="myPeriod" defaultValue="3s"/>
        <route>
            <from uri="timer:{{name}}?period={{myPeriod}}"/>
            <setBody><simple>{{greeting}} ${body}</simple></setBody>
            <log message="${body}"/>
        </route>
    </routeTemplate>
</routeTemplates>

Other route DSLs

Since Camel Quarkus 1.8.0, you can also use Java jOOR, Groovy, YAML, Kotlin or JavaScript for defining Camel routes.

These are mostly motivated by Apache Camel K and its project-less approach to defining Camel routes. With Camel K, all you need to run an integration is a file where the routes are defined using one of the supported DSLs. With Camel Quarkus you still need a pom.xml file with the appropriate dependencies in addition to the route definition files. Except for YAML, these DSLs are supported only in JVM mode, because they load and compile the routes at runtime.

What’s next?

We recommend to continue with Configuration.