Kettle (Pentaho PDI): how to visit all steps of a Job - pentaho

Question

I need to visit all steps contained in Kettle's .ktr file using Java.
I'm using
KettleEnvironment.init();
JobMeta jobMeta = new JobMeta("file.kjb", null);
Job job = new Job(null, jobMeta);
but not Job nor JobMeta seem to provide any method for visiting the job to the basic steps.

Answer 1

According to this answer, apparently it is not possible.

Answer 2

So, I have managed to do it using a combination of DelegationListener and TransListener, however, I am not sure if DelegationListener is required here. Maybe there is another way to add TransListeners to Transformation Job Entries:
package testTransformationsInJob;
import java.util.List;
import org.pentaho.di.core.KettleEnvironment;
import org.pentaho.di.core.exception.KettleException;
import org.pentaho.di.job.DelegationListener;
import org.pentaho.di.job.Job;
import org.pentaho.di.job.JobExecutionConfiguration;
import org.pentaho.di.job.JobMeta;
import org.pentaho.di.trans.Trans;
import org.pentaho.di.trans.TransExecutionConfiguration;
import org.pentaho.di.trans.TransListener;
import org.pentaho.di.trans.step.StepMetaDataCombi;
import org.pentaho.di.trans.step.StepInterface;
public class MainClass {
public MainClass() {
// TODO Auto-generated constructor stub
}
private static class MyTransListener implements TransListener {
#Override
public void transActive(Trans arg0) {
// TODO Auto-generated method stub
}
#Override
public void transFinished(Trans arg0) throws KettleException {
// TODO Auto-generated method stub
}
#Override
public void transStarted(Trans delegatedTrans) throws KettleException {
List<StepMetaDataCombi> stepCombis = delegatedTrans.getSteps();
if(stepCombis == null) {
return;
}
for(StepMetaDataCombi stepCombi: stepCombis) {
StepInterface step = stepCombi.step;
//
// Do some useful work here.
//
System.out.println("\t" + step.getStepname());
}
}
}
private static class MyDelegationListener implements DelegationListener {
private TransListener transListener;
MyDelegationListener(TransListener transListener) {
this.transListener = transListener;
}
#Override
public void jobDelegationStarted(Job delegatedJob,
JobExecutionConfiguration jobExecutionConfiguration) {
// TODO Auto-generated method stub
}
#Override
public void transformationDelegationStarted(Trans delegatedTrans,
TransExecutionConfiguration transExecutionConfiguratioStep) {
System.out.println("transformationDelegationStarted");
System.out.println(delegatedTrans.getName());
// transformationDelegationStarted() is called after Trans object is constructed
// but before it is executed.
// However, we can't access steps at this point using delegatedTrans.getSteps()
// since steps are constructed somewhere in execute method.
// However, we can add TransListener here, which will be able to iterate steps.
delegatedTrans.addTransListener(this.transListener);
}
}
public static void main(String[] args) throws KettleException {
KettleEnvironment.init();
JobMeta jobMeta = new JobMeta("d:\\test_job.kjb", null);
Job job = new Job(null, jobMeta);
// Here I add a DelegationListener, which will add a TransListener to every Trans in job.
// Not sure though if using DelegationListener is a right way to access Transformation Job Entries
// Maybe there is a more elegant way to do it.
MyTransListener myTransListener = new MyTransListener();
DelegationListener delegationListener = new MyDelegationListener(myTransListener);
job.addDelegationListener(delegationListener);
job.start();
job.waitUntilFinished();
}
}
And here is the output I get:
2016/07/07 09:47:37 - test_job - Start of job execution
2016/07/07 09:47:37 - test_job - Starting entry [Transformation]
2016/07/07 09:47:37 - Transformation - Loading transformation from XML file [file:///d://test.ktr]
transformationDelegationStarted
test
2016/07/07 09:47:37 - test - Dispatching started for transformation [test]
Detect empty stream
User Defined Java Class
2016/07/07 09:47:37 - Detect empty stream.0 - Finished processing (I=0, O=0, R=0, W=1, U=0, E=0)
2016/07/07 09:47:38 - User Defined Java Class.0 - Finished processing (I=0, O=0, R=1, W=1, U=0, E=0)
2016/07/07 09:47:38 - test_job - Finished job entry [Transformation] (result=[true])
2016/07/07 09:47:38 - test_job - Job execution finished