问题
Currently in my Mac I have these JAVA versions:
MyMac$ cd /Library/Java/JavaVirtualMachines
$ ls -la
total 0
drwxr-xr-x 4 root wheel 136 17 Oct 11:21 .
drwxrwxr-x 5 root wheel 170 17 Oct 11:21 ..
drwxr-xr-x 3 root wheel 102 14 Jul 22:52 1.6.0.jdk
drwxr-xr-x 3 root wheel 102 17 Oct 11:16 jdk1.7.0_79.jdk
What I am trying to do is change the symbolic link to point to JDK 7 instead of JDK 6:
$cd /System/Library/Frameworks/JavaVM.framework/Versions
$ls -la
drwxr-xr-x 11 root wheel 374 17 Oct 11:21 .
drwxr-xr-x 10 root wheel 340 17 Oct 11:21 ..
lrwxr-xr-x 1 root wheel 10 17 Oct 11:21 1.4 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 17 Oct 11:21 1.4.2 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 17 Oct 11:21 1.5 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 17 Oct 11:21 1.5.0 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 17 Oct 11:21 1.6 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 17 Oct 11:21 1.6.0 -> CurrentJDK
drwxr-xr-x 8 root wheel 272 17 Oct 11:21 A
lrwxr-xr-x 1 root wheel 1 17 Oct 11:21 Current -> A
lrwxr-xr-x 1 root wheel 52 17 Oct 11:21 CurrentJDK -> /Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents
Unfortunately I cannot remove the link. I am getting an operation not permitted error:
sudo rm CurrentJDK
rm: CurrentJDK: Operation not permitted
Any ideas?
Thank you!
回答1:
El Capitan new feature: System Integrity Protection (SIP), was the cause of this problem. I had to disable SIP first.
Follow these steps to disable SIP:
Restart your Mac. Before OS X starts up, hold down Command-R and keep it held down until you see an Apple icon and a progress bar. Release. This boots you into Recovery. From the Utilities menu, select Terminal. At the prompt type exactly the following and then press Return:
csrutil disable
Terminal should display a message that SIP was disabled.
From the apple menu, select Restart.
You can re-enable SIP by following the above steps, but using csrutil enable instead.
回答2:
If you're running OS X 10.11 (El Capitan), there is a new feature called "Rootless" which prevents editing of files under /System/ except by installers and the like. You may be able to solve whatever problem is requiring you to update the CurrentJDK symlink just by setting the JAVA_HOME environment variable to /Library/Java/JavaVirtualMachines/jdk1.7.0_79.jdk/Contents/Home
If you truly want to modify that /System/Library/Frameworks/JavaVM.framework/Versions/CurrentJDK symlink, you will likely have have to disable Rootless mode. You could also try running the Java 7 installer again, though I'm not certain that this will work
More information on the Rootless feature can be found here: https://apple.stackexchange.com/questions/193368/what-is-the-rootless-feature-in-el-capitan-really
回答3:
Steps that worked on macOS Catalina 10.15.2 and RStudio 1.2.5036
Install Java 11.0.1 from here (requires free account):
https://www.oracle.com/technetwork/java/javase/downloads/java-archive-javase11-5116896.html
Run javareconf
You probably need to run the command below, but RStudio seems not acknowledge the settings:
sudo R CMD javareconf
Remove (if installed) and reinstall rJava from source
remove.packages("rJava")
install.packages("rJava", type="source", repos="http://cran.rstudio.com")
Installing rJava from source seems to run a different configuration setup that will look for Java and it will display "checking Java support in R" as part of the output that seems accepted by RStudio.
Change ~/.Rprofile
This change to .Rprofile may also be necessary:
options(java.home="/Library/Java/JavaVirtualMachines/jdk-11.0.1.jdk/Contents/Home")
Sys.setenv(DYLD_FALLBACK_LIBRARY_PATH="/Library/Java/JavaVirtualMachines/jdk-11.0.1.jdk/Contents/Home/lib/server/")
来源：https://stackoverflow.com/questions/33186166/how-change-currentjdk-symbolic-link-in-macos