PDI sources provide example implementations of job entries. Each PDI core job entry is located in a sub-package of
org.pentaho.di.job.entries found in the engine/src folder. The corresponding
dialog class is located in
org.pentaho.di.ui.job.entries found in the ui/src folder.
For example, these are the classes that make up the File Exists job entry:
dialog classes of the core PDI job entries are located in a different package and source folder. They are also assembled into a separate jar file. This allows PDI to load the UI-related jar file when launching Spoon and avoid loading the UI-related jar when it is not needed.