Using Autowiring for Testing RMI Services in Spring

Scehduling can be a common requirement in many applications. However testing such an application that used RMI with JUnit and JMock in a Spring-Maven environment turned out to be a little tricky for me. Thanks to the help of a colleague (thanks Mudassir!) and some head banging, I was able to find a way: Autowiring.

Generally my basic JUnit test cases have the following features:
1. The whole class annotated by @RunWith(JMock.class) - org.junit.runner.RunWith;
2. A set up method (the init method) annotated with @Before - org.junit.Before
3. The test cases annotated @Test - org.junit.Test
4. JUnit4Mockery used to mock relevant interfaces - org.jmock.integration.junit4.JUnit4Mockery
5. The usual expectatons and assertions
6. Spring adds punch with ability to mock request, response, sessions - org.springframework.mock.web.*

A Simple Test Case

Works fine for most things. Now picture this: you are developing application that needs to check stock prices every five minutes and send alerts to registered users if need be. Lets say there are three modules being developed for it: the user interface using which a user may register for an alert for stock price, the scheduler that keeps track of these alerts and the workflow engine that takes care of the alerts once fired. A classic MVC approach so far.

The controller accepts alerts from user interface and schedules Jobs that forward all information to the workflow. Let us assume these three modules are being developed by three different teams sitting in three corners of the world (ok, may be three corners of the office or just three different/independent machines/servers).

Now, when you are making the controller, you are essentially dependent on view for input and on the model for feedback (if any) for your input. We can provide access to our controller using any RMI strategy. For our example, we consider Spring's HttpInvoker. We intend to write a a test case to test the controller module.

Our controller has a remote service running in a spring environment. If it had been a simple servlet listening to ordinary post/get requests, writing a test case with MockHttpRequest would be a piece of cake. However when it is an RMI service, what mock up to use? An answer can be a test class looking something like this:

A Test Case For RMI Service


The answer lies in using SpringJUnit4ClassRunner and then auto-wiring the HttpInvokerService. ContextConfiguration points to the locations for the config xml. In the current case you should put it in "myPackage. If you are using Maven, the resources folder would be the right place to put it. The config file may look like:

Autowiring Config


If you are using Maven, don't forget to add the following dependencies:

Maven Dependencies

A few tweaks may be needed to suit your case but this should give you a general idea about using autowiring for your test cases in JUnit, JMock, Spring, Maven environment.