r - How to clear memory used by rJava?

Question

I am using xlsx package to create workbook, worksheet, write data to the sheet and then save the workbook. However, when I repeat this set of actions for several times, I start

Answer 1

I do not know how to do it on xlsx, in fact I no longer use it because of those issues

I now use XLConnect, and it has a command

xlcFreeMemory()

to do just that

Please note that for best results you need to increase Java memory before youload it as follows

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

Good luck

Answer 2

Piggy-backing the above answer to note that you don't need XLConnect to accomplish the effects of xlcFreeMemory... just note that what xlcFreeMemory actually does is to run the following:

gc()
J("java.lang.Runtime")$getRuntime()$gc()

That is, it runs gc() first in your R environment and then in the existing Java instance's environment.