Global EJB Client Side Interceptors Configuration

In  ejb

Overview

The goal of this issue is to implement client side EJB interceptors that can be configured system-wide through ejb3 subsystem configuration.

Issue

Dev Contacts

  • mailto:tadamski@redhat.com

QE Contacts

Testing By

[ ] Engineering

[x] QE

Affected Projects or Components

EJB

Requirements

  • Interceptors are implemented and packed inside the custom modules

  • Interceptors should be configured in the subsystem configuration and not in deployments

  • Interceptors conform to jboss-ejb-client interceptor API

Solution draft

Subystem XML

EJB3 subsystem is extended with <client-interceptors> tag containing a number of <interceptor> children tags. <interceptor> tags contains attributes for the module and the class of the interceptor. Sample XML fragment:

<client-interceptors>
	<interceptor module="org.abccorp:tracing-interceptors:1.0" class="org.abccorp.TracingInterceptor"/>
	<interceptor module="org.abccorp:timers-interceptors:1.1" class="org.abccorp.TimerInterceptors"/>
</client-interceptors>

Management model

The management model is as follows: client interceptors are represented as object list attribute of ejb3 subystem. Each object in the list contains two fields:

  • module: the name of the module in which the interceptor is implemented

  • class: the interceptor class

DMR model:

[standalone@localhost:9990 subsystem=ejb3] :read-attribute(name=client-interceptors)
{
    "outcome" => "success",
    "result" => [
        {
            "module" => "test",
            "class" => "org.testsuite.ejb.clientinterceptor.TestClientInterceptor"
        },
        {
            "module" => "my-interceptors",
            "class" => "org.mycompany.interceptors.CoolInterceptor"
        }
    ]
}

Any change to client-interceptors attribute should move server to the reload-required state.

Interceptor class

  • Interceptors implement org.jboss.ejb.client.EJBClientInterceptor interface

Sample client-interceptor class:

package org.jboss.as.test.multinode.interceptor;

import org.jboss.ejb.client.EJBClientInterceptor;
import org.jboss.ejb.client.EJBClientInvocationContext;

public class ClientInterceptor implements EJBClientInterceptor {

    @Override
    public void handleInvocation(EJBClientInvocationContext context) throws Exception {
        context.sendRequest();
    }

    @Override
    public Object handleInvocationResult(EJBClientInvocationContext context) throws Exception {
        return context.getResult();
    }
}

Interceptor module

Client interceptor classes should be located in a module and place in $JBOSS_HOME/modules directory.

Draft implementation

The draft implementation of client-interceptors is already done and works: https://github.com/tadamski/wildfly/tree/WFLY-6144.

Test Plan

Community Documentation

Part of the PR.