The execution process of kettle’s job

How to execute a kettle job in Spoon GUI or command line after we create a job in Spoon GUI? In Spoon GUI,the main class is “org.pentaho.di.ui.spoon.Spoon.java”.This class handles the main window of the Spoon graphical transformation editor.Many operations about a job or transformation such as run,debug,preview,zoomIn,etc,are all in this class.This post just writes about the code execution process.

When we start a job or transformation,Spoon invokes the method runFile(),and then is distributed to executeTransformation() or executeJob().At now,we mainly study about executeJob() method.

This is a simple sequence diagram below.It contains several classes for Starting to execute a job using execute(int nr, Result result) in Job.java.We can see the relation of these classes from it.

What is the detail process of job execution? You should look into the Job.run() method for detail information.