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Showing posts with label Development Environment. Show all posts
Showing posts with label Development Environment. Show all posts

Wednesday, June 11, 2008

Generating IBM RSA Websphere projects with Maven

Rational Software Architect (RSA) may not be the best development environment, but when it comes to WAS-integrated IDEs, there are not that many choices. RSA is the familiar Eclipse packaged together with some plugins, which provide integration with Websphere. Starting with a Websphere Web application with RSA is easy - just choose the right project type and you can immediately run the application in Websphere from the IDE.

If you are working with Maven, however, there are very good reasons why you will not want to create any projects drom RSA. All of them boil down to the DRY principle - Don't Repeat Yourself. The Maven POM files already describe your projects and dependencies, why would you want to do this second time in RSA? You are going to make your release builds (and continuous integration) with Maven anyway, and any RSA project changes you make have no impact on the build. You may end up bulding something different than what you develop. Maintaining dependencies at two places - in maven poms and in your RSA project is not good, and Maven is much better in the dependency stuff.

Besides, why lock to RSA? If you can generate the IDE files for RSA/Websphere, so you can for Eclipse/Tomcat, for example.

The Maven Eclipse plugin generates the needed IDE files. The point is you want to be able to use them directly in RSA. It took me some time to get the POMs right, so I thought it is worth sharing.

Typically in a Websphere app, you have an EAR project, a Web project and several JAR projects. In this example, I start with 3 projects: ERA, WAR, JAR. Define them in the parent POM:



<modules>
<module>app-jar</module>
<module>app-web</module>
<module>app-ear</module>
<modules>


Further in the parent POM, declare you are using java 5.0:


<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.5</source>
<target>1.5</target>
</configuration>
</plugin>


N.B. Define 1.5 and not 5.0, this was fatal for my RSA installation!

There's nothing special about the JAR project, the generated eclipse project is fine. For the Web project, few more settings are essential. Assuming you have a maven webapp archetype project, include the following under build/plugins in the project's pom:


<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-eclipse-plugin</artifactId>
<configuration>
<wtpversion>1.5</wtpversion>
<wtpContextName>myapp</wtpContextName>
<additionalProjectFacets>
<jst.java>5.0</jst.java>
<com.ibm.websphere.extended.web>6.1</com.ibm.websphere.extended.web>
<com.ibm.websphere.coexistence.web>6.1</com.ibm.websphere.coexistence.web>
</additionalProjectFacets>
</configuration>
</plugin>


The generated project will be a Dynamic Java project, and RSA wil recognise src/main/webapp as the web root folder. The web context name is also define in the plugin settings.

Similar setting are needed for the EAR POM:



<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-eclipse-plugin</artifactId>
<configuration>
<wtpversion>1.5</wtpversion>
<additionalProjectFacets>
<jst.ear>1.4</jst.ear>
<com.ibm.websphere.extended.web>
6.1
</com.ibm.websphere.extended.web>
<com.ibm.websphere.coexistence.web>
6.1
</com.ibm.websphere.coexistence.web>
</additionalProjectFacets>
</configuration>
</plugin>


The generated project is recognized by RSA as an EAR project. Of course, you need a correct application.xml in src/main/application/META-INF. This project doesn't contain any code, but is still usefull for maven, as it will build the release EAR.

Once that all is done, go the the project root and run mvn eclipse:eclipse with any extra options you may need. Import the generated projects in RSA (File/Import/Existing projects int workspace). The resulting file structure is the well known maven webapp structure:



To run the application from RSA, drag the EAR project to 'Web Sphere Application Sever' in the Servers view and start te server.

There is one issue that has not been addressed here - how do you get all those WAS-specific IBM files. Update follows.

Profiles

It's a good idea to set all those settings in maven under a profile. For the next environment, add a new profile.

Hiccups

Yes, they are very present:
- Go to the app-web project, Properties, J2EE dependencies, Web libraries - all library dependencies are there but not the project dependency on app-dom, while it obviously should be. Add it. I couldn't find a solution for this, tips about it will be very appreciated.
- Make sure that the web module element in application.xml has no id attribute. The id runs out of sync each time project files are generated.
- Sadly enough, after fiddling with application and server deployment configuration, now and then I just have to restart RSA to make the web application running.

Sunday, April 27, 2008

Portlet development with Eclipse and Pluto

I had to set up a portlet development environment with Eclipse. The portlet is being built with Spring Portlet MVC 2.5.2 and will eventually run under Websphere, but Eclipse WTP and Websphere don't go together well. So I thought I'll try to run my portlet from Eclipse/WTP in a portlet container running under Tomcat. Pluto is such a container and does the job. It has its own peculiarities, it needs to generate its own web.xml using your web.xml and portlet.xml as input. Pluto provides an ant task to do this.

A good integration with eclipse and Maven should take care of the following issues:
- dependency management: download the needed Pluto ant task jar with all its dependencies.
- automatically generate web.xml for Pluto each time when needed - in Eclipse and during a Maven build.

The steps I took to get all nicely running:
1. Install Tomcat/Pluto bundle and configre it as a server in eclipse.
2. Tell Maven to save together all dependencies needed for the Pluto Ant Task.
3. Define an Ant build file with the Pluto task.
4. Add the execution of the Ant task in the Maven build.
5. Generate eclipse project, add the portlet application to the pluto server, run the server end configure a page with the portlet. It is fun to have more portlet instances on the same page.
6. Fix issues that prevent the portlet from running.
7. Define an Eclipse Custom Builder to update the web.xml automatically.

Once this is done, start Tomcat/Pluto from eclipse, log in as admin and add your portlet to a Pluto portal page. After that, just start the server and go to your portal page.

The details of how to perform the above steps:

Install Tomcat/Pluto bundle and configre it as a server in eclipse

I installed pluto 1.1.6 based on tomcat 5.5 - pluto-current-bundle.zip from http://archive.apache.org/dist/portals/pluto/

In the Eclipse Servers tab, define a new Apache Tomcat 5.5 server. IMPORTANT: In the server configuration page, select 'Use Tomcat installation (takes control of tomcat installation)' under Server locations. I don't understande why, but otherwise pluto doesn't see the portlet.


Tell Maven to save together all dependencies needed for the Pluto Ant Task.


First of all, the org.apache.pluto:pluto-ant-tasks dependency must be present in your (root) pom.xml. Then, add the following, preferably under a new profile pluto:


<profile>
<id>pluto</id>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<executions>
<execution>
<id>copy-dependencies</id>
<phase>generate-resources</phase>
<goals>
<goal>copy-dependencies</goal>
</goals>
<configuration>
<outputDirectory>target/libs-for-pluto</outputDirectory>
<includeArtifactIds>
pluto-ant-tasks,pluto-util,pluto-descriptor-api,pluto-descriptor-impl,commons-logging,castor,xercesImpl
</includeArtifactIds>
</configuration>
</execution>
. . .


This way, all dependencies needed for the Pluto ant task will be copied in target/libs-for-pluto folder where they can be used by the ant task.

Define an Ant build file with the Pluto task

In a new file, e.g. generate-pluto-web-xml.xml, define the task which generates the web.xml file needed by pluto in the web-inf folder. A place is needed for the original web.xml that will be procerssd by the task, I've placed it in src/main/config.

The contents of update-web-xml.xml:

<project name="pluto-update-web-xml" basedir="." default="generate-web-xml">
<path id="pluto.task.classes" >
<fileset dir="target/libs-for-pluto" includes="**/*" />
</path>

<typedef name="passemble"
classname="org.apache.pluto.ant.AssembleTask" classpathref="pluto.task.classes" />

<target name="generate-web-xml">
<echo>Generating Pluto web.xml</echo>
<passemble webxml="src/main/config/web.xml"
portletxml="src/main/webapp/web-inf/portlet.xml"
destfile="src/main/webapp/web-inf/web.xml" />
</target>

</project>

At this point, you should be able to run this ant task from the command line. It is better to do this from maven, see next step.

Add the execution of the Ant task in the Maven build.
In pom.xml, add the following under the profile pluto:

<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-antrun-plugin</artifactId>
<executions>
<execution>
<phase>generate-resources</phase>
<configuration>
<tasks>
<ant antfile="${basedir}/generate-pluto-web-xml.xml">
<target name="generate-web-xml" />
</ant>
</tasks>
</configuration>
<goals>
<goal>run</goal>
</goals>
</execution>
</executions>
</plugin>


At this point, running manually
mvn eclipse:eclipse -P pluto
will produce a web.xml as needed for pluto. The original web.xml stays in src/main/config. Needless to say, you must have a good portlet.xml in src/main/webapp/WEB-INF. Don't forget to make it a Web project.

Configure your portlet in Pluto
That is pretty straightforward - go to the Admin tab in pulto, and add your portlet to a new or existing page. The portlets in the application you deployed on pluto should be visible in the Portlet Application list box on the admin page.
Fix issues

When I first started the page with the portlet, I got the following stack trace:

java.lang.ClassCastException: org.springframework.web.servlet.support.JstlUtils$SpringLocalizationContext cannot be cast to java.lang.String
org.apache.taglibs.standard.tag.common.fmt.BundleSupport.getLocalizationContext(BundleSupport.java:134)
org.apache.taglibs.standard.tag.common.fmt.SetLocaleSupport.getFormattingLocale(SetLocaleSupport.java:251)
org.apache.taglibs.standard.tag.common.fmt.FormatDateSupport.doEndTag(FormatDateSupport.java:116)
org.apache.jsp.WEB_002dINF.themes.pluto_002ddefault_002dtheme_jsp._jspx_meth_fmt_formatDate_0(pluto_002ddefault_002dtheme_jsp.java:602)


Whatever the reason, I just removed the tag causing the error: a tag in pluto-default-theme.jsp and voila, it worked.

Define an Eclipse Custom Builder to update the web.xml automatically

You can define a custom bulder to update your web.xml in src/main/webapp/WEB-INF automatically each time you build the project or change web.xml in src/main/config. That's not really necessary, unless you are going to change web.xml often.

Alternatively, run mvn generate-resources manually each time you change web.xml.

To define a custom builder:

- In Eclipse, go to Project properties, Builders. New, Ant Builder.
In the Main tab, select the ant file and the working folder.


In the Refresh tab, select Specific Resources an click on Specify Resources. Select src/main/webapp/WEB-INF/web.xml. After each build, eclipse will refresh this resource.

In the Build Options tab, check 'Specify working set of relevant resources'. Click on Specify resources and select main/webapp/config/web.xml.

Now each time you change this file you see the ant task output in the console and the file is updated.