How do I import rests from other XML files?

Since Camel 2.14

When defining rests in Camel using Xml Configuration you may want to define some rests in other XML files. For example you may have many rest services and it may help to maintain the application if some of the rests are in separate XML files. You may also want to store common and reusable rests in other XML files, which you can simply import when needed.

This is possible to define rests outside <camelContext/> which you do in a new <restContext/> tag.

When you use <restContext> then they are separated, and cannot reuse existing <onException>, <intercept>, <dataFormats> and similar cross cutting functionality defined in the <camelContext>. In other words the <restContext> is currently isolated. This may change in Camel 3.x.

For example we could have a file named myCoolRests.xml which contains a rest (can have more) as shown:

  <restContext id="myCoolRest" xmlns="http://camel.apache.org/schema/spring">
    <rest uri="/say/hello">
      <get>
        <to uri="direct:hello"/>
      </get>
    </rest>
  </restContext>

Then in your XML file which contains the CamelContext you can use Spring to import the myCoolRests.xml file. And then inside <camelContext/> you can refer to the <restContext/> using the <restContextRef> by its id as shown below:

  <camelContext xmlns="http://camel.apache.org/schema/spring">

    <restContextRef ref="myCoolRest"/>

    <rest uri="/say/bye">
      <get consumes="application/json">
        <to uri="direct:bye"/>
      </get>
      <post>
        <to uri="mock:update"/>
      </post>
    </rest>

    <route>
      <from uri="direct:hello"/>
      <transform>
        <constant>Hello World</constant>
      </transform>
    </route>
    <route>
      <from uri="direct:bye"/>
      <transform>
        <constant>Bye World</constant>
      </transform>
    </route>
  </camelContext>

Also notice that you can mix and match, having rests inside CamelContext and also externalized in RestContext.

You can have as many <restContextRef/> as you like.

Reusable rests

The rests defined in <restContext/> can be reused by multiple <camelContext/>. However its only the definition which is reused. At runtime each CamelContext will create its own instance of the rest based on the definition.