Unable to load rJava on R

问题:

I wish to load rJava in R x64 3.1.2. OS- Windows 8.1 64 bit

Though installation seems to work fine:

  > install.packages("rJava")
    Installing package into ‘C:/Users/sony/Documents/R/win-library/3.1’
    (as ‘lib’ is unspecified)
    --- Please select a CRAN mirror for use in this session ---
    trying URL 'http://cran.utstat.utoronto.ca/bin/windows/contrib/3.1/rJava_0.9-6.zip'
    Content type 'application/zip' length 758898 bytes (741 Kb)
    opened URL
    downloaded 741 Kb

package ‘rJava’ successfully unpacked and MD5 sums checked

The downloaded binary packages are in
        C:\Users\sony\AppData\Local\Temp\RtmpamYUH7\downloaded_packages

I get an error while loading the package:

library(rJava)
Error in get(Info[i, 1], envir = env) : 
  lazy-load database 'C:/Users/sony/Documents/R/win-library/3.1/rJava/R/rJava.rdb' is corrupt
In addition: Warning message:
In get(Info[i, 1], envir = env) : internal error -3 in R_decompress1
Error: package or namespace load failed for ‘rJava’

I know that I am working on R-64 bit and at same time the environment variable Path is set to:

C:\Program Files\Java\jdk1.7.0_51\bin;C:\Program Files\Java\jre7\bin\server;

also, so the Java version is 64 bit too. I don't understand the reason behind the error.

On manually setting through R:

options(java.home="C:\\Program Files\\Java\\jdk1.7.0_51\\bin")
library(rJava)

I get this 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/sony/Documents/R/win-library/3.1/rJava/libs/x64/rJava.dll':
  LoadLibrary failure:  The specified module could not be found.

Error: package or namespace load failed for ‘rJava’

Any advice? The error seems to have cropped up after I uninstalled some old version of Java.

OTHERS: Also just to add, I do not set JAVA_HOME as a environment variable.

Uninstalling and Reinstalling R also doesn't seem to fix the problem.

Removing older java versions is too of no help.

回答1:

Use:

Sys.setenv(JAVA_HOME='...path to JRE...')

e.g.

Sys.setenv(JAVA_HOME='C:\\Program Files\\Java\\jdk1.7.0_51\\jre')

Your environment variable is wrong.

回答2:

I got a similar error:

> library(rJava)
Error : .onLoad failed in loadNamespace() for 'rJava', details:
  call: inDL(x, as.logical(local), as.logical(now), ...)
  error: unable to load shared object 'C:/program files/R/R-3.1.2/library/rJava/libs/x64/rJava.dll':
  LoadLibrary failure:  The specified module could not be found.

My JAVA_HOME was pointing to JDK, rather than JRE.

> Sys.getenv("JAVA_HOME")
[1] "c:\\java\\jdk1.7.0_55"
> Sys.setenv(JAVA_HOME="c:\\java\\jdk1.7.0_55\\jre")

I could now load rJava and xlsx in R.

回答3:

I've met a similar problem and spent an entire day to get it fixed. Although my computer, windows7, and Rstudio are 64 bit, but my Java is 32 bit(!) Once I realized that, I download a 64 bit Java. I have to manually download, the automatic download will lead to the 32 bit version because my chrome browser is 32 bit. 64 bit Java will be automatically installed in

C:\Program Files\Java, however, 32 bit Java will be automatically installed in C:\Program Files (x86) \Java.

This is an important indicator telling me my Java is 64 bit or 32 bit.

After installing the 64 bit Java, everything works perfect!

回答4:

I get this error every time Java sneaks an update onto my PC. When I go:

Sys.getenv("Path")

I find something in the output which looks like

C:\\Program Files \\Java\\jre1.8.0_112\\bin\\server\\

where the last few digits of the jre subfolder are outdated.

To fix this everywhere, you might want to edit the Windows environment variable. Do this by going WINDOWS + X key, selecting Command Prompt (Admin) from the menu, and typing

rundll32.exe sysdm.cpl,EditEnvironmentVariables

in the command box. This will call up this dialog box with edit rights for the PATH variable (and other system variables):

The Windows interface for editing long environment variables is a bit unwieldy, so after I click Edit... I like to copy-paste the resulting mess of paths to Notepad.exe, do the work there, and copy-paste back.

回答5:

Faced similar error message.

Tried a few steps listed here.

1. Set Env. Variable, JAVA_HOME. => Didn't work.
2. Tried to install rJava +> Didn't work Steps 3,4,5 worked..
3. Updated my Java 64 bit version 8.xx (latest available)
4. install.packages(rJava) ==> Success
5. install.packages(RWeka) ==> Success

回答6:

Had the same issue:

I was running 64-bit R you can check which version by closing and re-openning RStudio. It should be at the top.

I had 32-bit java installed i.e. Java folder was within C:\Program Files (x86).

I simply went on to Java.com and downloaded the 64-bit Java and added it's location at the end of the PATH in System variables and I can load rJava now. (The installation asked me to get rid of the old version which I did)

回答7:

It is probably the issue with the setting with the JAVA_HOME pointer. In case you do not have JDK but JRE, here is you might have to do: Sys.setenv(JAVA_HOME='C:\Program Files\Java\jre1.8.0_161')

Remember to change the numbers after "jre" based on what you have on your computer. Here is a link that explains the difference between JDK and JRE.

回答8:

Try downloading the RStudio daily build: http://dailies.rstudio.com

It worked for me on the second try after I tried everything else (updated R, Rstudio, Java, reinstalled rJava a million times, and followed all the stackoverflow advice).

The tip came from the RStudio support forums:

RStudio is indeed failing to read some of the start-up information normally provided by R here...

We have a potential fix for this in the latest daily builds of RStudio -- if you're willing, you can try downloading and testing from http://dailies.rstudio.com