rJava -- NLP, java heap error

I'm trying to run the NLP and openNLP packages in R with rJava, and I keep getting a similar error: Java.lang.OutOfMemoryError: Java heap space.

I've already tried:

options( java.parameters = "-Xmx4g" ) library( "RWeka" )

I've also tried increasing to 8g. Still running out of space, still crashing R.

I'm working on annotating a .txt file-- a large one, yes, but just one file. Trying to extract location names. Any ideas how I can fix this issue?

Thanks!