在macOS High Sierra（Java 9环境）下安装rJava遇问题求助

Hey there, let’s work through this rJava installation headache together—conflicting Java versions (Apple Java 6 + Oracle Java 9) are almost certainly the culprit here. Here’s a step-by-step fix that’s worked for me and other community members:

1. Lock in Oracle Java 9 as Your Active Environment #

First, we need to make sure the system prioritizes Java 9 over Apple Java 6:

• Locate your Oracle Java 9 install path (it’s typically this, but double-check if yours differs):

  /Library/Java/JavaVirtualMachines/jdk-9.jdk/Contents/Home
  

• Set your JAVA_HOME to point directly to this path:

  export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk-9.jdk/Contents/Home
  

• Verify you’re using Java 9 with these commands (both should output Java 9 version info):

  java -version
  javac -version
  

2. Reconfigure R to Use Java 9 #

Your earlier sudo R CMD javareconf probably picked up Apple Java 6 instead of Java 9. Let’s force it to use the correct version:

sudo R CMD javareconf JAVA_HOME=$JAVA_HOME

This ensures R links to Java 9’s headers and libraries instead of the older Apple Java 6.

3. Clean Up Partial rJava Installs (If Any) #

If you’ve tried installing rJava before, remove any leftover files to avoid conflicts:

• Open R (don’t use sudo) and run:

  if ("rJava" %in% installed.packages()) remove.packages("rJava")
  

• Quit R once this finishes.

4. Install rJava from Source with Correct Flags #

Before installing, set up preprocessor flags to point to Java 9’s macOS-specific headers:

export JAVA_CPPFLAGS="-I${JAVA_HOME}/include -I${JAVA_HOME}/include/darwin"

Now install rJava without unsetting JAVA_HOME (we’ve already configured it correctly):

R --quiet -e 'install.packages("rJava", type="source", repos="http://cran.us.r-project.org")'

Note: Never use sudo to install R packages—it can cause permission issues down the line.

5. Verify the Installation #

Open R and test if rJava loads properly:

library(rJava)
.jinit()

If no errors appear, you’re all set!

Quick Troubleshooting #

• If you see a "JNI_CreateJavaVM failed" error: Restart your terminal to reset lingering environment variables, then double-check JAVA_HOME and re-run javareconf.
• If header files are missing: Confirm the JAVA_CPPFLAGS path matches your Java 9 install—macOS stores JNI headers in the include/darwin subfolder.

内容的提问来源于stack exchange，提问作者Christopher Costello