In allegato i file con i messaggi in italiano della libreria "pentaho-reporting-engine-classic-core-3.9.1-GA.jar". Occorre inserirli nel jar, nelle corrispondenti directory.

I attach the Italian translation of messages for library "pentaho-reporting-engine-classic-core-3.9.1-GA.jar". You have to insert them in the corresponding directory.
pentaho_3.9.1_it_it.zip