Java R Interface (JRI) Setup

Question

I am trying to setup the Java/R interface (bundled in the R "rJava" package), but I am having some trouble (despite trying many suggestions here and on other forums).

I am running Windows 7, jdk1.7.0_05, Eclipse, R 2.15.2. These are all 64 bit installations.

The steps I have followed to attempt to get the example running are as follows:

1. Install rJava within the R GUI: install.packages('rJava') - installs to C:\Users\USERNAME\Documents\R\win-library\2.15\rJava\
2. Setup environment variables: R_HOME = "C:\Program Files\R\R-2.15.2", additions to PATH = "C:\Program Files\Java\jdk1.7.0_05\bin";"C:\Program Files\Java\jdk1.7.0_05\jre\bin\server";"C:\Program Files\R\R-2.15.2\bin\x64";"C:\Users\USERNAME\Documents\R\win-library\2.15\rJava\jri\x64"
3. Setup example project in Eclipse, setting VM argument: -Djava.library.path="C:\Users\USERNAME\Documents\R\win-library\2.15\rJava\jri\x64"
4. Restart R and load rJava with command: libraries('rJava')
5. Run the example program, obtaining the following exception:

Cannot find JRI native library! Please make sure that the JRI native library is in a directory listed in java.library.path.

java.lang.UnsatisfiedLinkError: C:\Users\USERNAME\Documents\R\win-library\2.15\rJava\jri\x64\jri.dll: Can't find dependent libraries
    at java.lang.ClassLoader$NativeLibrary.load(Native Method)
    at java.lang.ClassLoader.loadLibrary1(Unknown Source)
    at java.lang.ClassLoader.loadLibrary0(Unknown Source)
    at java.lang.ClassLoader.loadLibrary(Unknown Source)
    at java.lang.Runtime.loadLibrary0(Unknown Source)
    at java.lang.System.loadLibrary(Unknown Source)
    at org.rosuda.JRI.Rengine.<clinit>(Rengine.java:19)
    at test.JRITest.main(JRITest.java:64)

I have verified "java.library.path" is set as expected since: System.out.println("JLP = " + System.getProperty("java.library.path")); outputs the correct path.

I think rJava may not have installed fully (have tried reinstalling), but I'm not sure how to check this. The only JAR in "...\rJava\jri" or any of its subdirectories is "JRI.jar" and the examples directory seems incomplete.

Does anyone have suggestions on what may be going wrong here?

It seems the JRI website (http://www.rforge.net/JRI/index.html) has been down today, not sure if anyone knows another source to download from (other than direct from CRAN).

Thanks.

Answer 1

Try to copy all dll files(*.dll) which in R directory to JAVA_PATH/bin. After that load the the jri native lib like:

//Right under your R class
   static {
    System.loadLibrary("jri");      
   }

I had the same problem and solved it by this method.

Thx

Answer 2

After reading a lot of posts and trying a lot of different solutions, it is finally working. I'm using Windows 7 64bits and I'll list the steps that I did to make it work properly.

1. Install package rJava using R install.packages("rJava")
2. Right-click on My Computer > Properties > Advanced System Settings > Environment Variables...
3. Find Var PATH or CLASSPATH and Edit, add the following paths: C:\Program Files\R\R-3.4.0\bin\x64;C:\Users\ [User Name]\Documents\R\win-library\3.4\rJava\jri\x64
4. Go to C:\Program Files\R\R-3.4.0\bin\x64 and copy all .dll files (here they are: R.dll,Rblas.dll,Rgraphapp.dll,Riconv.dll,Rlapack.dll)
5. Past them at C:\Program Files\Java\jdk1.8.0_144\bin
6. When you create your java project, remeber to add the JRI.jar, JRIEngine.jar and Rengine.jar to your project build path. They are located at C:\Users\ [User name]\Documents\R\win-library\3.4\rJava\jri
7. After doing all this, I was still getting an error, that was solved when I went to C:\Users\ [User Name]\Documents\R\win-library\3.4\rJava\jri\x64 and copy the jri.dll and past inside my Java Project, like the following image:

Here is a code example and its output:

This example was retrieved from: http://codophile.com/2015/04/15/how-to-integrate-r-with-java-using-rjava/

Answer 3

I got same issue. Resolved by add R bin to path(my OS is x64).

path=C:\Program Files\R\R-3.2.2\bin\x64

Anyway, you can find out which dll is the dependent one by use this tool http://dependencywalker.com/

Answer 4

Fellows, after few days of trying and failing I figured out my ultimate solution like:

• the following files must be copied to directory C:/Program Files/RapidMiner/RapidMiner Studio/jre/bin/:

  • jri.dll from C:/Users/Public/Documents/Documentos/R/win-library/3.0/rJava/jri/x64/
  • all files from C:/Program Files/R/R-3.0.3/bin/x64/

• so on RM Studio Tools tab Preferences option, Start-up tab, after checking Initialize extensions the Extensions directory must be C:\Program Files\RapidMiner\RapidMiner Studio\jre\bin\R.exe and on R tab Native lib must be C:\Program Files\RapidMiner\RapidMiner Studio\jre\bin\jri.dll

Easy, isn't it? Thank you all for the advices.

Answer 5

Here's another option: add the directories of rJava and R where the dlls reside into the PATH variable, either at the Computer level or in an ant script like this for example (x64 for 64 bit installs, i386 for 32 bit, depending on your local installation):

<java fork="true" classname="${run.class}">
  <env key="PATH" path="C:/Users/myuser/Documents/R/win-library/3.0/rJava/jri/x64;C:/Program Files/R/R-3.0.2/bin/x64"/>
  <classpath>
     <path refid="run.test.classpath"/>
  </classpath>
</java>