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

The last question has an easy answer:

> .Machine$sizeof.pointer
[1] 8

Meaning I am running R64. If I were running 32 bit R it would return 4. Just because you are running a 64 bit OS does not mean you will be running 64 bit R, and from the error message it appears you are not.

EDIT: If the package has binaries, then they are in separate directories. The specifics will depend on the OS. Notice that your LoadLibrary error occurred when it attempted to find the dll in ...rJava/libs/x64/... On my MacOS system the ...rJava/libs/...` folder has 3 subdirectories: i386, ppc, and x86_64. (The ppc files are obviously useless baggage.)

Answer 2

Update (July 2018):

The latest CRAN version of rJava will find the jvm.dll automatically, without manually setting the PATH or JAVA_HOME. However note that:

• To use rJava in 32-bit R, you need Java for Windows x86
• To use rJava in 64-bit R, you need Java for Windows x64
• To build or check R packages with multi-arch (the default) you need to install both Java For Windows x64 as well as Java for Windows x86. On Win 64, the former installs in C:\Program files\Java\ and the latter in C:\Program Files (x86)\Java\ so they do not conflict.

As of Java version 9, support for x86 (win32) has been discontinued. Hence the latest working multi-arch setup is to install both jdk-8u172-windows-i586.exe and jdk-8u172-windows-x64.exe and then the binary package from CRAN:

install.packages("rJava")

The binary package from CRAN should pick up on the jvm by itself. Experts only: to build rJava from source, you need the --merge-multiarch flag:

install.packages('rJava', type = 'source', INSTALL_opts='--merge-multiarch')

---

Old anwser:

(Note: many of folks in other answers/comments have said to remove JAVA_HOME, so consider that. I have not revisited this issue recently to know if all the steps below are still necessary.)

Here is some quick advice on how to get up and running with R + rJava on Windows 7 64bit. There are several possibilities, but most have fatal flaws. Here is what worked for me:

Add jvm.dll to your PATH

rJava, the R<->Java bridge, will need jvm.dll, but R will have trouble finding that DLL. It resides in a folder like

C:\Program Files\Java\jdk1.6.0_25\jre\bin\server

or

C:\Program Files\Java\jre6\jre\bin\client

Wherever yours is, add that directory to your windows PATH variable. (Windows -> "Path" -> "Edit environment variables to for your account" -> PATH -> edit the value.)

You may already have Java on your PATH. If so you should find the client/server directory in the same Java "home" dir as the one already on your PATH.

To be safe, make sure your architectures match.If you have Java in Program Files, it is 64-bit, so you ought to run R64. If you have Java in Program Files (x86), that's 32-bit, so you use plain 32-bit R.

Re-launch R from the Windows Menu

If R is running, quit.

From the Start Menu , Start R / RGUI, RStudio. This is very important, to make R pick up your PATH changes.

Install rJava 0.9.2.

Earlier versions do not work! Mirrors are not up-to-date, so go to the source at www.rforge.net: http://www.rforge.net/rJava/files/. Note the advice there

“Please use

`install.packages('rJava',,'http://www.rforge.net/')`

to install.”

That is almost correct. This actually works:

install.packages('rJava', .libPaths()[1], 'http://www.rforge.net/')

Watch the punctuation! The mysterious “.libPaths()[1],” just tells R to install the package in the primary library directory. For some reason, leaving the value blank doesn’t work, even though it should default.

Answer 3

I had some trouble determining the Java package that was installed when I ran into this problem, since the previous answers didn't exactly work for me. To sort it out, I typed:

Sys.setenv(JAVA_HOME="C:/Program Files/Java/

and then hit tab and the two suggested directories were "jre1.8.0_31/" and "jre7/"

Jre7 didn't solve my problem, but jre1.8.0_31/ did. Final answer was running (before library(rJava)):

Sys.setenv(JAVA_HOME="C:/Program Files/Java/jre1.8.0_31/")

I'm using 64-bit Windows 8.1 Hope this helps someone else.

Update:

Check your version to determine what X should be (mine has changed several times since this post):

Sys.setenv(JAVA_HOME="C:/Program Files/Java/jre1.8.0_x/")

Answer 4

I had a related problem with rJava. It would load but a package that depends on it, would not load.

Users may waste a lot of time with jvm.dll and PATH and JAVA_HOME when the real fix is to force the installer to just forget about i386. Use option for install.packages. (this also works when drat library is used. (credit goes to Dason)

install.packages("SqlRender",INSTALL_opts="--no-multiarch")

Also, you can modify just your user path with a win command like this:

setx PATH "C:\Program Files\Java\jre1.8.0_102\bin\server;%PATH%"

Answer 5

I think this is an update. I was unable to install rJava (on Windows) until I installed the JDK, as per Javac is not found and javac not working in windows command prompt. The message I was getting was

'javac' is not recognized as an internal or external command, operable program or batch file.

The JDK includes the JRE, and according to https://cran.r-project.org/web/packages/rJava/index.html the current version (0.9-7 published 2015-Jul-29) of rJava

SystemRequirements:     Java JDK 1.2 or higher (for JRI/REngine JDK 1.4 or higher), GNU make

So there you are: if rJava won't install because it can't find javac, and you have the JRE installed, then try the JDK. Also, make sure that JAVA_HOME points to the JDK and not the JRE.

Answer 6

For me, setting JAVA_HOME did the trick (instead of unsetting, as in another answer given here). Either in Windows:

set JAVA_HOME="C:\Program Files\Java\jre7\"

Or inside R:

Sys.setenv(JAVA_HOME="C:\\Program Files\\Java\\jre7\\")

But what's probably the best solution (since rJava 0.9-4) is overriding within R the Windows JAVA_HOME setting altogether:

options(java.home="C:\\Program Files\\Java\\jre7\\")
library(rJava)