topic Re: Activiti and Karaf in Alfresco Archive

Activiti and Karaf

bkonrad — Tue, 12 Aug 2014 11:25:50 GMT

Activiti 5.16 is now OSGi compatible and Apache Karaf is a great environment to run Activiti. After some time I managed to install the engine as bundles in Apache Karaf. My first question is: Is there a standard provisioning for installing Activiti in Karaf (i.e. a feature.xml)?What I did is to impl

Re: Activiti and Karaf

trademak — Tue, 12 Aug 2014 12:50:39 GMT

No there's no standard provisioning in the Activiti project for Karaf. I did create one for my Activiti in Action book though.
The stack trace you included doesn't show classloading issues to me. Or is there more information in the stack trace?

Best regards,

Re: Activiti and Karaf

bkonrad — Tue, 12 Aug 2014 13:00:33 GMT

I took a look into the activiti sources and saw a method in DefaultProcessDiagramCanvas
<code>
public DefaultProcessDiagramCanvas(int width, int height, int minX, int minY, String imageType,
String activityFontName, String labelFontName, ClassLoader customClassLoader) {
…
}
</code>
which indicates, that you can use another ClassLoader which breaks OSGi principles 😞

Re: Activiti and Karaf

arnoldschrijve1 — Tue, 12 Aug 2014 13:13:25 GMT

There is this Github project by axemblr: https://github.com/axemblr/activiti-karaf
But it is about 2 years old and targets Activiti 5.10. Upgrading it to newest version and dependencies will require quite a bit of effort.

Also there are issues with Spring 4.x used by the latest Activiti version, which no longer offers native support for OSGi. As an alternative the jars are 'rebundled' by the guys on the Apache ServiceMix project, and a Karaf feature is available to install them: http://repo1.maven.org/maven2/org/apache/karaf/features/spring/3.0.1/spring-3.0.1-features.xml

This feature.xml also contains the spring-dm feature, where the version-range is modified, so Spring 4 is included. But for spring-dm the continued compatibility with new Spring releases is a bit uncertain.

Re: Activiti and Karaf

bkonrad — Tue, 12 Aug 2014 14:39:43 GMT

@trademak: Basicly, I did the same as you in the book-osgi-app (I like the idea of deploying seperate process osgi bundles), but the problem of generating the process image is still there. Can you reproduce this issue?
I know the https://github.com/axemblr/activiti-karaf project but is not update-to-date and unnecessary complicated.

Re: Activiti and Karaf

bkonrad — Wed, 13 Aug 2014 08:27:19 GMT

I solved the problem by doing some "hacks" - but is there a way to remove the ugly classLoader functionality from org.activiti.image.util.ReflectUtil??

Set the ClassLoader:
<code>
<bean id="processEngineConfiguration" class="org.activiti.spring.SpringProcessEngineConfiguration">
<property name="dataSource" ref="dataSource" />
<property name="transactionManager" ref="transactionManager" />
<property name="databaseSchemaUpdate" value="true" />
<property name="jobExecutorActivate" value="true" />
<property name="enableDatabaseEventLogging" value="true" />
<property name="classLoader" ref="classLoader" />
</bean>

<bean id="classLoader" factory-bean="classLoaderFactory" factory-method="getObject" />

<bean id="classLoaderFactory" class="my.ClassLoaderFactoryBean" />
</code>

<code>
public class ClassLoaderFactoryBean implements BundleContextAware {

private BundleContext bundleContext;

public void setBundleContext(BundleContext bundleContext) {
this.bundleContext = bundleContext;
}

public ClassLoader getObject() {
Bundle bundle = this.bundleContext.getBundle();
return bundle.adapt(BundleWiring.class).getClassLoader();
}

}
</code>

Embed the images:
<code>
<Embed-Transitive>true</Embed-Transitive>
<Embed-Dependency>artifactId=activiti-image-generator;inline=org/activiti/icons/**</Embed-Dependency>
</code>