> What is the correct parameter name ?
Try "ApplicationName" [1]. Also, you can set it on the Connectionobject after creation via the JDBC standard setClientInfo(...)method[2].
[1]: https://github.com/pgjdbc/pgjdbc/blob/master/org/postgresql/core/v3/ConnectionFactoryImpl.java#L639[2]: http://docs.oracle.com/javase/7/docs/api/java/sql/Connection.html#setClientInfo%28java.lang.String,%20java.lang.String%29
-S