Using the rJava package on Win7 64 bit with R

Question

I'm trying to install rJava on a computer with Win 7 64 bit. When I run

install.packages("rJava")

everything seems to be fine:

Installing package(s) into ‘C:/Users/djq/Documents/R/win-library/2.13’
(as ‘lib’ is unspecified)
trying URL 'http://software.rc.fas.harvard.edu/mirrors/R/bin/windows/contrib/2.13/rJava_0.9-1.zip'
Content type 'application/zip' length 654936 bytes (639 Kb)
opened URL
downloaded 639 Kb

package 'rJava' successfully unpacked and MD5 sums checked

The downloaded packages are in
    C:\TEMP\RtmpW2eAUw\downloaded_packages

but when I tried to load the library library(rJava) I get the following error:

Error : .onLoad failed in loadNamespace() for 'rJava', details:
  call: inDL(x, as.logical(local), as.logical(now), ...)
  error: unable to load shared object 'C:/Users/me/Documents/R/win-library/2.13/rJava/libs/x64/rJava.dll':
  LoadLibrary failure:  %1 is not a valid Win32 application.

Error: package/namespace load failed for 'rJava'

I have installed the Java JRE (trying both 32 and 64 bit versions) and the JDK (using both 32 and 64 bit). My R version is R version 2.13.1 (2011-07-08) and I'm using RStudio.

If I try using 32 bit R, I can load rJava fine. Is the problem just that rJava does not run in R 64 bit? How can I tell if a package is just for 32 instead of 64?

---

edit: just posted R.version():

> R.Version()
$platform
[1] "x86_64-pc-mingw32"

$arch
[1] "x86_64"

$os
[1] "mingw32"

$system
[1] "x86_64, mingw32"

$status
[1] ""

$major
[1] "2"

$minor
[1] "13.1"

$year
[1] "2011"

$month
[1] "07"

$day
[1] "08"

$`svn rev`
[1] "56322"

$language
[1] "R"

$version.string
[1] "R version 2.13.1 (2011-07-08)"

Answer 1

Getting rJava to work depends heavily on your computers configuration:

1. You have to use the same 32bit or 64bit version for both: R and JDK/JRE. A mixture of this will never work (at least for me).

2. If you use 64bit version make sure, that you do not set JAVA_HOME as a enviorment variable. If this variable is set, rJava will not work for whatever reason (at least for me). You can check easily within R is JAVA_HOME is set with

   Sys.getenv("JAVA_HOME")
   

If you need to have JAVA_HOME set (e.g. you need it for maven or something else), you could deactivate it within your R-session with the following code before loading rJava:

if (Sys.getenv("JAVA_HOME")!="")
  Sys.setenv(JAVA_HOME="")
library(rJava)

This should do the trick in most cases. Furthermore this will fix issue Using the rJava package on Win7 64 bit with R, too. I borrowed the idea of unsetting the enviorment variable from R: rJava package install failing.

Answer 2

I solved the issue by uninstalling apparently redundant Java software from my windows 7 x64 machine. I achieved this by first uninstalling all Java applications and then installing a fresh Java version. (Later I pointed R 3.4.3 x86_64-w64-mingw32 to the Java path, just to mention though I don't think this was the real issue.) Today only Java 8 Update 161 (64-bit) 8.0.1610.12 was left then. After this, install.packages("rJava"); library(rJava) did work perfectly.

Answer 3

I need to have a 32 bit JRE available for my browser, but 64 bit JRE for R and rJava. The 32 bit JRE is installed in the default location. After some experimentation, I found that I only needed one of misterbee's suggestions to get rJava (version 0.9-6) working for me. All I did was add the path to my 64 bit java installation:

C:\apps\Java\jre\bin\server\jvm.dll

to the top of my path environment variable (your path will likely be different) and remove my JAVA_HOME as user2161065 suggested. I put this just ahead of the entry

C:\ProgramData\Oracle\Java\javapath

which the Oracle installer inserts at the top of the path and points to some symlinks to the 32 bit JRE. By adding the entry to 64 bit jvm.dll, looks like rJava could find what it needs.

Answer 4

Sorry for necro. I have too run into the same issue and found out that rJava expects JAVA_HOME to point to JRE. If you have JDK installed, most probably your JAVA_HOME points to JDK. My quick solution:

Sys.setenv(JAVA_HOME=paste(Sys.getenv("JAVA_HOME"), "jre", sep="\\"))