sneakybeaky/scrtest

OSGi SCR tests

SCR Annotation Tests

Introduction

This project has some very basic demonstrations of OSGi Declarative Services use with the Apache Felix SCR annotations. The project serves as a basis to examine the behaviour of DS and serve as a basis for further experimentation.

Installing

To run this demo, first build this project

mvn clean install

Now download the latest Karaf distribution, unpack & run. In the console do

karaf@root> features:install webconsole-scr
karaf@root> install -s mvn:com.ninedemons/com.ninedemons.scrtest/1.1-SNAPSHOT

Service dynamism

Look at the karaf log and you should see an entry like this

Got a new simple service Simple Service One
Simple service one doing something

This shows the consumer getting an instance of SimpleService and invoking it. Now use the SCR web console tab and stop the com.ninedemons.scrtest.simple.provider.SimpleServiceOne component (click on the stop button in the action column).

You will see an entry like this

Unbinding our current simple service Simple Service One

This shows the callback in the consumer has been invoked when the service is unbound. If you refresh the web page you will also see the consumer service (com.ninedemons.scrtest.simple.consumer.Consumer) is no longer active as it's dependency can no longer be satisfied.

If you now start both services (com.ninedemons.scrtest.simple.provider.SimpleServiceOne and com.ninedemons.scrtest.simple.provider.SimpleServiceTwo) you will see the consumer has also been started with SimpleServiceOne being supplied as a dependency, even though two are available.

Service ranking

Stop the Consumer service and make sure both SimpleService implementations are running - the Consumer status should be disabled and both SimpleService status should be registered.

Now start the consumer and see which SimpleService is supplied as the dependency. Repeat this but disable SimpleServiceOne, and then see that SimpleServiceTwo is supplied as the dependency.

Configuration Factory, Configuration management & cardinality

In your browser now go to http://127.0.0.1:8181/system/console/configMgr and look for the Goodbye World Config factory and click on it to add a new config. When you save you should see something like this in the karaf log

 Got new goodbye service with prefix Goodbye
 Goodbye Bob!

As you add or remove more configurations you will see them being invoked by the consuming service. The code for this part lives in the com.ninedemons.scrtest.multiple package.