IBM DeveloperWorks Spring Roo Part 5 : Writing Advanced and Wrapper Addons

Today fifth part of my Spring Roo series got published at IBM DeveloperWorks. This article-cum-tutorial talks about how you can write advanced and wrapper Spring Roo add-ons. Checkout the article at

Spring Roo Add-on Release Problems

I am writing a add-on for deploying Spring Roo applications to OpenShift Express cloud just like the Cloud Foundry Spring Roo add-on. The add-on is available at But I face problems when I release the add-on using Maven Release plugin (mvn release:prepare release:perform). So, this is simple guide to help me next time I face these issues.

  1. SnapShot Dependencies : The first problem I face is that my add-on depend on OpenShift Java client which is available as Snapshot dependency. So, I need to ignore the snapshot dependencies. This is not recommeded but some times you don’t have any other solution. For more information refer to this post
    mvn release:prepare release:perform -DignoreSnapshots=true
  2. Adding Third Party Jars in an OSGI bundle. I have blogged this at
  3. The third problem I face is that svn client is not able to authenticate with Google Code. The exception that I get is shown below. To fix this I specify username and password with mvn release command as shown below.
    mvn release:prepare release:perform -DignoreSnapshots=true -Dpassword=password

    The exception that I get is

    [ERROR] Failed to execute goal org.apache.maven.plugins:maven-release-plugin:2.2:prepare (default-cli) on project org.xebia.roo.addon.openshift: Unable to commit files
    [ERROR] Provider message:
    [ERROR] The svn command failed.
    [ERROR] Command output:
    [ERROR] svn: Commit failed (details follow):
    [ERROR] svn: MKACTIVITY of '/svn/!svn/act/b8000ba7-c3c6-4bb2-9d3b-bd3c1db73dd3': authorization failed: Could not authenticate to server: rejected Basic challenge (
    [ERROR] -> [Help 1]
    [ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
    [ERROR] Re-run Maven using the -X switch to enable full debug logging.
    [ERROR] For more information about the errors and possible solutions, please read the following articles:
    [ERROR] [Help 1]

Deploying Application To OpenShift Express using Spring Roo OpenShift Express Add-on

Last couple of years Spring Roo has been one of my favorite tool to rapidly build Spring applications for demo, POC, and learning new technologies. With Spring Roo Cloud Foundry integration you can not only build applications rapidly but deploy to Cloud Foundry public cloud with a couple of commands. In case you are not aware of Spring Roo and Cloud Foundry you can refer to my Spring Roo series on IBM DeveloperWorks. From last 5-6 months I have been following OpenShift platform as a service and I am really in love with OpenShift Express because of its feature set and simplicity. In case you are not aware of OpenShift Express please refer to the documentation. There are two ways Java applications can be deployed to express — using ruby command line tool called RHC and using Eclipse plugin. Personally I like rhc command line more than eclipse plugin. The rhc command line tool is great but you should have ruby runtime installed on your machine. Being Spring Roo afficianado I decided to write Spring Roo OpenShift Express add-on to create, deploy, add cartridges from with Roo shell. This can be thought of as a third way to deploy applications to OpenShift Express. The project is hosted on Google Code at In this blog I will show you how you can install the add-on, create a template OpenShift Express application, convert that application to a Spring MongoDB application using Spring Roo, and finally deploy application to OpenShift Express.  You can read the full blog at my company blog

Spring Roo CompareTo Add-on Released

Over the weekend I created an advanced Spring Roo add-on to provide support for creation of compareTo method. This add-on is on similar lines of Spring Roo own equals add-on which provide implementation of equals and hashcode methods. The add-on is released and available for community to use. The add-on is listed in Spring Roo repository XML . It is built using Spring Roo latest version 1.2.0.RC1. This post will talk about how to install and use the add-on.

Installing the compareTo add-on

Open the operating system command line and type roo. In case you don’t have Spring Roo setup please refer to my IBM DeveloperWork article on Spring Roo. After the roo shell initiates type the following command to install the add-on.

addon install bundle --bundleSymbolicName org.xebia.roo.addon.compareto

If you don’t have automatic pgp trust enable you will see a message on Roo shell saying that you first have to trust my pgp key before you can install the add-on. To trust the key type the following Roo command.

pgp trust --keyId 0x9B68220C

Once it is enable re-run the addon install command and add-on should get installed. To verify that add-on is installed type the osgi ps command and you should compareto add-on listed at the bottom of the command output.

[  78] [Active     ] [    1] spring-dw-roo-compareto-addon (0.1.1.BUILD)

This add-on exposes two commands compareto setup and compareto and these commands are enabled after you have created entity. This is because before you have created any entity it does not make sense to have compareTo method.

Using the compareTo add-on

Lets first create a simple bookshop application. Type the following command which will create the project, setup database and create a simple book entity.

project --topLevelPackage com.xebia.bookshop --projectName bookshop
jpa setup --database HYPERSONIC_IN_MEMORY --provider HIBERNATE
entity jpa --class ~.domain.Book --testAutomatically
field string --fieldName title --notNull
field string --fieldName author --notNull
field number --type double --fieldName price --notNull

After you have ran the commands above you can now create compareTo method for book entity.To create the compareTo method type the following commands.

compareto setup
compareto add --type ~.domain.Book

The first command will add the required dependencies and second will create the Book_Roo_Compareto.aj ITD which contains the compareTo method.

If you want to exclude some fields in compareTo method you should specify i.e. if you don’t want author and price field to be used in compareTo method you can specify them in excludeFields attribute as shown below.

compareto add --type ~.domain.Book --excludeFields "author price"

Use this add-on and share feedback.

Introducing Spring Roo, Part 3: Developing Spring Roo add-ons

Spring Roo is a RAD tool that lets you build applications (mainly web) quickly and easily. Under the hood, Spring Roo is based on OSGI add-on architecture, which makes it easy to extend Spring Roo by adding add-ons. Spring Roo provides commands to create add-ons that can be very easily made available to the Spring Roo user community. In this article, we first talk about Spring Roo architecture, talking about how Spring Roo leverages its own add-on architecture to provide different features, then we will create add-ons using the Roo shell and modify them to suit our needs. Please read the third article at IBM DeveloperWorks.