GGBLOG – Single Source OSGi Enterprise Architecture Pattern

The following article documents an architectural solution to a problem which I’ve encountered in many enterprise computing environments.

Problem:

There are a wide variety of deployment artifacts which cannot be reused between different deployment environments. Copies of the artifacts are taken and modifications are made to enable compatibility for each different execution environments. Component dependencies on different deployment environments cause the code base to diverge over time and become specific to a particular execution environment. This causes the enterprise code base to grow exponentially for only a linear increase in functionality.

Solution and Consequence:

Utilise OSGi as the execution back plane for service, web and desktop applications. This solution delivers a unified approach to the creation, deployment and management of enterprise bundles. The consequence is that a linear relationship is formed between adding enterprise functionality and the size of the code base that enables it.

Structure:

The diagram below shows the architectural structure of this pattern.

Example Strategy and Code:

Example code is available for download at:

https://sourceforge.net/project/showfiles.php?group_id=228168&package_id=301845

Download OSGiEAPattern.zip

The example strategy and code makes use of:

1) Equinox as the OSGi execution environment,

2) Rich Ajax Platform as the rich web application

3) Rich Client Platform as the rich desktop application,

4) Apache CXF as the Web Service consumer

5) JAX-WS as the service layer

Installing the example code:

Pre requisites:

1) Install eclipse 3.4 (http://www.eclipse.org/downloads/download.php?file=/technology/epp/downloads/release/ganymede/SR1/eclipse-java-ganymede-SR1-win32.zip)

2) Install the Rich Client Platform (http://www.eclipse.org/rap/gettingstarted.php)

Running the Rich Desktop Application

Start eclipse and new workspace.

Click window -> prefererences -> Plug in development -> target platform -> tick group plug-ins by location, Select or ensure that the target platform location is the standard directory and not pointing to the rich ajax platform plugins.

Click File -> import -> Existing projects into workspace:

Click next -> select archive file -> browse and select the OSGiEAPattern.zip which you can download from https://sourceforge.net/project/showfiles.php?group_id=228168&package_id=301845

Deselect galang.research.rap.hello and click finish

Select Run configurations -> select OSGi -> select new –> deselect workspace and target platform -> tick galang.research.esb -> add required bundles, you should now have 13 bundles selected

Click Run then double click plugin.xml within galang.research.rcp.hello -> click overview

click Launch eclipse application and type in your name and click “Call web service”

Running the Rich Web Application

Ensure that you have installed the Rich Ajax Platform.

http://www.eclipse.org/rap/gettingstarted.php

Start eclipse and a new workspace.

Click window -> prefererences -> Plug in development -> target platform -> tick group plug-ins by location, Select or ensure that the target platform location is the pointing to the rich ajax platform plugins which is located at [ECLIPSE_HOME]/ configuration/org.eclipse.rap.target-1.1.1/eclipse

Click File -> import -> Existing projects into workspace:

Click next -> select archive file -> browse and select the workspaces.zip which you can downloaded from

https://sourceforge.net/project/showfiles.php?group_id=228168&package_id=301845

Download OSGiEAPattern.zip

Deselect galang.research.rcp.hello and click finish

Right click galang.research.rap.hello.launch

type in your name click Call web service

If you have any questions or want to work with me to implement a strategy for this pattern based on your java technology stack feel free to drop me a line (glenn.galang@gmail.com).

Related Articles:

OSGi

http://ggalangblog.blogspot.com/2008/11/ggblog-light-weight-reporting-server-on.html

RAP

http://ggalangblog.blogspot.com/2008/11/ggblog-chat-on-rap.html

RCP

http://ggalangblog.blogspot.com/2008/11/ggblog-dynamic-jface-xml-tableviewer.html