Running Java in debug mode using Apache Ant

Configure your Java task as given below;

<java classname="org.zero.Main" fork="true" failonerror="true">
            <sysproperty key="DEBUG" value="true" />
            <jvmarg value="-Xdebug" />
            <jvmarg value="-Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=8999" />
            <jvmarg value="-Xnoagent" />
            <jvmarg value="-Djava.compiler=none" />
            <arg value="${project.root}/conf/preferences.xml" />
            <classpath refid="project.classpath" />
        </java>

Further,  configure your eclipse debug remote application to listen to the specified port (8999 in this case).

Also, add Thread.sleep(1000); as the first line in your main method.

Execute Java task and try connecting from eclipse, you may need to increase the thread sleep time.

Approach: How to improve traceability between BPMN process model and UML component model

Workflow can be modeled with a Business Process Diagram or an Acivity Diagram and can be transformed manually or otherwise using underlying matamodel. However, the challenge lies in finding convergence of object-oriented approach offered by UML and process-centric approach taken by BPMN. To put this in context, it should be noted that UML methods asks you to find the objects first using the static structure diagrams and only then build dynamic behaviour diagram to model object interaction. In an attempt to satisfy the stated need, we can model our 'draft' activity model based upon Business Process Diagram as specified by BPMN at the 'first attempt' and 'later' the 'technical team' can refine and refactor the activity diagram so created in few iterations between static diagrams (class diagram etc.) and activity diagram to model the dynamic behaviour, which can improve the traceability.

For a detailed study of the subject one may be interested to study "Process Modeling Notations and Workflow Patterns" here.