RestEASY Interceptor Not Being Called

Question

I've created a RestEASY Interceptor to allow me to set header values on the HTTP response after my webservice call has completed. My code looks like this...

@Provider
@ServerInterceptor
@Precedence("HEADER_DECORATORS")
public class MyHeaderInterceptor implements
        MessageBodyWriterInterceptor {

    @Override
    public void write(MessageBodyWriterContext context) throws IOException,
            WebApplicationException {

             ....do stuff here....
        }
}

When I make a call to my service, however, the interceptor is never called. I see the webservice call complete successfully, but none of the code in my interceptor is ever executed. Is there anything beyond this that I need to do to register my interceptor? Does it have to be declared anywhere else? Are there any special web.xml parameters that need to be included?

Answer 1

You have to list the interceptor in the resteasy.providers context-param of your web.xml. Adding annotation to the Interceptor class is not enough.

<context-param>
      <param-name>resteasy.providers</param-name>
      <param-value>org.resteasy.test.ejb.exception.FooExceptionMapper</param-value>
</context-param>

Answer 2

As for Resteasy 2.x you could also have it to automatically scan WEB-INF/lib jars and WEB-INF/classes directory for both @Provider and JAX-RS resource classes (@Path, @GET, @POST etc..) and register them:

<context-param>
    <param-name>resteasy.scan</param-name>
    <param-value>true</param-value>
</context-param>

Or can have Resteasy to Scan for @Provider classes and register them :

<context-param>
    <param-name>resteasy.scan.providers</param-name>
    <param-value>true</param-value>
</context-param>

In both cases you dont have to list the interceptors explicitly into web.xml.

Otherwise if both context-params 'resteasy.scan' and 'resteasy.scan.providers' are not enabled (and they are disabled by default) you may want to specify a comma delimited list of fully qualified @Provider class names you want to register inside the 'resteasy.providers' element:

<context-param>
    <param-name>resteasy.providers</param-name>
    <param-value>com.test.Interceptor1,com.test.Interceptor2</param-value>
</context-param>

That's taken from the doc : http://docs.jboss.org/resteasy/docs/2.3.3.Final/userguide/html_single/index.html#d0e72