Manually register a plugin - plugins

Question

I'm trying to run a transformation using PDI embedded in Java code but I get an error about missing plugin (looks like it is the Abort step).
I know I can use KETTLE_PLUGIN_BASE_FOLDERS so that PDI loads it automatically (that works), but in order to make my app simpler I would like to manually register this plugin using Java, how can I do that?
I'm following examples provided here https://github.com/pentaho/pdi-sdk-plugins/tree/master/kettle-sdk-embedding-samples
2019/08/14 17:03:07 - Could not find on destination DB.0 - ERROR (version 8.2.0.7-719, build 8.2.0.7-719 from 2019-06-24 02.06.35 by buildguy) : Can't run transformation due to plugin missing
2019/08/14 17:03:07 - Could not find on source DB.0 - ERROR (version 8.2.0.7-719, build 8.2.0.7-719 from 2019-06-24 02.06.35 by buildguy) : Can't run transformation due to plugin missing
2019/08/14 17:03:07 - Could not find on destination DB.0 - ERROR (version 8.2.0.7-719, build 8.2.0.7-719 from 2019-06-24 02.06.35 by buildguy) : Error initializing step [Could not find on destination DB]
2019/08/14 17:03:07 - Could not find on source DB.0 - ERROR (version 8.2.0.7-719, build 8.2.0.7-719 from 2019-06-24 02.06.35 by buildguy) : Error initializing step [Could not find on source DB]
2019/08/14 17:03:07 - Could not find on destination DB 2.0 - ERROR (version 8.2.0.7-719, build 8.2.0.7-719 from 2019-06-24 02.06.35 by buildguy) : Can't run transformation due to plugin missing
2019/08/14 17:03:07 - Could not find on destination DB 2.0 - ERROR (version 8.2.0.7-719, build 8.2.0.7-719 from 2019-06-24 02.06.35 by buildguy) : Error initializing step [Could not find on destination DB 2]
2019/08/14 17:03:07 - Abort.0 - ERROR (version 8.2.0.7-719, build 8.2.0.7-719 from 2019-06-24 02.06.35 by buildguy) : Can't run transformation due to plugin missing
2019/08/14 17:03:07 - Abort.0 - ERROR (version 8.2.0.7-719, build 8.2.0.7-719 from 2019-06-24 02.06.35 by buildguy) : Error initializing step [Abort]

Answer 1

To register a plugin you must set a system property, KETTLE_PLUGIN_CLASSES, with the fully qualified class name of the plugins meta-class before you initialize your KettleEnvironment. The property can be a comma-separated string of all plugins you wish to register.
This is an example of how to register a plugin:
void initEnv() {
// Register plugins here
System.setProperty("KETTLE_PLUGIN_CLASSES","org.pentaho.di.trans.steps.jsoninput.JsonInputMeta");
try {
KettleEnvironment.init();
} catch (KettleException e) {
e.printStackTrace();
}
}
This example registers the JSON Input step which is a core plugin. In order for PDI to successfully load the plugin, it's jar-file must be available on the classpath.