Problem loading rJava

I finally solved the problem:

It seems that rJava searches for jvm.dll in ~\Java\jre6\bin\client. However this folder didn´t exist on my system (jvm.dll was in ~\bin\server).

So I just made a copy of jvm.dll in a folder ~\bin\client\ and added this to the path.

Now everything works fine!

My problem was solved by

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

It was a package that depends on rJava and all advices were telling me to fix Java installation. But the solution was to use install option that simply forgets about i386 architecture. (also works with drat library and packages not from CRAN)

This may be due to a conflict between RStudio and Java versions. If you have installed 64 bit java and RStudio is running in 32 bit mode, you may experience problems like this. As a solution, you can change the 32-64 bit selection in the Tools-> Global Options-> General section in RStudio. You can find detailed information here.

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.