How do I switch between Java 7 and Java 6 on OS X 10.8.2?

Question

I am using Java SE 7 to program simple games for windows and mac, but I have to switch to java 6 to run games such as Minecraft on my computer. This used to work just fine before I updated to Mac OS X 10.8.2 Build 12C60.

Before this update I used to be able to open Java Preferences and check off Java 6 or Java 7. But now I don't seem to be able to find Java Preferences.

I am running OS X 10.8.2 (latest version).

score 99 · Answer 1 · edited Apr 02 '14 at 06:30

One can use the java_home mechanism more conveniently.

Say you have Java 7 as the default:

$ java -version
java version "1.7.0_15" 
…

Now let’s activate Java 6:

$export JAVA_HOME=$(/usr/libexec/java_home -v 1.6)

And there it is:

$ java -version
java version "1.6.0_41"
…

I added these to my .bashrc in order to make things even more convenient:

alias java_ls='/usr/libexec/java_home -V 2>&1 | grep -E "\d.\d.\d[,_]" | cut -d , -f 1 | colrm 1 4 | grep -v Home'

function java_use() {
    export JAVA_HOME=$(/usr/libexec/java_home -v $1)
    export PATH=$JAVA_HOME/bin:$PATH
    java -version
}

java_ls reduces the output of java_home -V to just the version numbers. And java_use is just a shortcut for what we did above. E.g. java_use 1.6 will switch to Java 6.

score 41 · Accepted Answer · edited Jul 24 '17 at 18:41

I don't think it's possible to switch JRE (runtime environments) see here:

http://docs.oracle.com/javase/7/docs/webnotes/install/mac/mac-jre.html

which states:

Only one JRE can be installed. Installing a JRE removes the previously installed JRE. The JRE version used by the system can be determined in one of two ways:

Workaround:

I had a similar problem like you have with Minecraft with Wuala. Where I needed to run Wuala using Java 1.6 whilst I needed to develop with JDK 1.7 and I managed this by opening the Wuala.app package and changing its startup script in:

/Applications/Wuala.app/Contents/MacOS/wuala

from:

exec java ${VMARGS} -cp "${JAR_DIR}/loader3.jar":/System/Library/Java/ com.wuala.loader3.Loader3 -alternateprogrampath "${JAR_DIR}" -installed $*

to:

/usr/libexec/java_home -v 1.6.0 --exec java ${VMARGS} -cp "${JAR_DIR}/loader3.jar":/System/Library/Java/ com.wuala.loader3.Loader3 -alternateprogrampath "${JAR_DIR}" -installed $*

I.e simply replacing: exec with: /usr/libexec/java_home -v 1.6.0 --exec

This is of course rather involved and will get broken every time wuala autoupdates but otherwise it works.

To use another JDK see here:

http://docs.oracle.com/javase/7/docs/webnotes/install/mac/mac-jdk.html

which states:

To run a different version of Java, either specify the full path, or use the java_home tool: /usr/libexec/java_home -v 1.7.0_06 --exec javac -version

Here is an illustration and examples from my setup:

Oracle JDK installs:

odin:~ geff$ ls -al /Library/Java/JavaVirtualMachines 
total 0
21058660 0 drwxr-xr-x  3 root  wheel  - 102 24 Oct 18:04:33 2012 jdk1.7.0_09.jdk/
21061692 0 drwxr-xr-x  3 root  wheel  - 102 24 Oct 18:06:08 2012 jdk1.7.0_07.jdk/
21042328 0 drwxrwxr-x  3 root  wheel  - 102 20 Apr 06:58:53 2012 1.7.0.jdk/
21031664 0 drwxrwxr-x  7 root  admin  - 238 24 Oct 18:04:16 2012 ../
21042327 0 drwxr-xr-x  5 root  wheel  - 170 24 Oct 18:06:13 2012 ./

Apple supplied JDK:

odin:~ geff$ ls -al /System/Library/Java/JavaVirtualMachines 
total 0
21026468 0 drwxr-xr-x  3 root  wheel  - 102  1 Nov 17:49:02 2011 1.6.0.jdk/
21026436 0 drwxr-xr-x  6 root  wheel  - 204 24 Mar 23:04:06 2012 ../
21026467 0 drwxr-xr-x  3 root  wheel  - 102  1 Nov 17:49:02 2011 ./

This works for me also to use the Apple supplied 1.6 JDK

odin:~ geff$ /usr/libexec/java_home -v 1.6.0_37 --exec java -version
java version "1.6.0_37"
Java(TM) SE Runtime Environment (build 1.6.0_37-b06-434-11M3909)
Java HotSpot(TM) 64-Bit Server VM (build 20.12-b01-434, mixed mode)

Choose between the 1.7 Oracle versions:

Selecting the first Oracle JDK 1.7.0_04

odin:~ geff$ /usr/libexec/java_home -v 1.7.0_04 --exec java -version
java version "1.7.0_04"
Java(TM) SE Runtime Environment (build 1.7.0_04-b21)
Java HotSpot(TM) 64-Bit Server VM (build 23.0-b21, mixed mode)

Selecting JDK 1.7.0_07

odin:~ geff$ /usr/libexec/java_home -v 1.7.0_07 --exec java -version
java version "1.7.0_07"
Java(TM) SE Runtime Environment (build 1.7.0_07-b10)
Java HotSpot(TM) 64-Bit Server VM (build 23.3-b01, mixed mode)

The default JDK is the highest one:

odin:~ geff$ java -version
java version "1.7.0_09"
Java(TM) SE Runtime Environment (build 1.7.0_09-b05)
Java HotSpot(TM) 64-Bit Server VM (build 23.5-b02, mixed mode)

Defaults to the highest "patch level when using only minor version number:

odin:~ geff$ /usr/libexec/java_home -v 1.7.0 --exec java -version
java version "1.7.0_09"
Java(TM) SE Runtime Environment (build 1.7.0_09-b05)
Java HotSpot(TM) 64-Bit Server VM (build 23.5-b02, mixed mode)

Neeme Praks · Answer 3 · 2021-04-07T22:59:12.710

A solution for easily switching the JDK (not sure about JRE), works with any JDK version, not just 6 and 7 (source):

Bash shell, add this function to your .bash_profile:

function setjdk() {  
  if [ $# -ne 0 ]; then  
   removeFromPath '/System/Library/Frameworks/JavaVM.framework/Home/bin'  
   if [ -n "${JAVA_HOME+x}" ]; then  
    removeFromPath $JAVA_HOME  
   fi
   unset JAVA_HOME # We need this on Big Sur, see https://developer.apple.com/forums/thread/666681
   export JAVA_HOME=`/usr/libexec/java_home -v $@`  
   export PATH=$JAVA_HOME/bin:$PATH  
   echo JAVA_HOME set to $JAVA_HOME  
   java -version  
  fi
 }  
 function removeFromPath() {  
  export PATH=$(echo $PATH | sed -E -e "s;:$1;;" -e "s;$1:?;;")  
 }

Fish shell, save this function as ~/.config/fish/functions/setjdk.fish:

function setjdk
  if [ (count $argv) -ne 0 ]
    set -g -x PATH (string match -v /System/Library/Frameworks/JavaVM.framework/Home/bin $PATH)
    if [ -n "$JAVA_HOME" ]
      set -g -x PATH (string match -v $JAVA_HOME $PATH)
    end
    set -e JAVA_HOME # We need this on Big Sur, see https://developer.apple.com/forums/thread/666681
    set -g -x JAVA_HOME (/usr/libexec/java_home -v $argv)
    set -g -x PATH $JAVA_HOME/bin $PATH
    echo JAVA_HOME set to $JAVA_HOME
    java -version
  end
end

Usage:

$ setjdk 1.7

score 7 · Answer 4 · answered Oct 23 '12 at 09:02

7

A quick workaround is to create a symlink to the old Java 6 binary:

sudo ln -s /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Commands/java /usr/local/bin/java6

Then run the apps with: java6 -jar myapp.jar

answered Oct 23 '12 at 09:02

stephendv

71

score 3 · Answer 5 · answered Oct 21 '12 at 14:58

The Java preferences app doesn't seem to list Java 1.6 anymore. However when I check java version in the command line I get:

java -version                                            
java version "1.6.0_37"
Java(TM) SE Runtime Environment (build 1.6.0_37-b06-434-11M3909)
Java HotSpot(TM) 64-Bit Server VM (build 20.12-b01-434, mixed mode)

score 3 · Answer 6 · answered May 16 '13 at 22:11

It's pretty simple to switch Java versions instantly on OS X without needing to change the $JAVA_HOME variable.

I am running 10.8.2, and my $JAVA_HOME variable points to /Library/Java/Home

echo $JAVA_HOME

This path is a symbolic link, as can be seen by running ls -l command

ls -la /Library/Java

The default symbolic link points to

Home -> /Library/Java/JavaVirtualMachines/1.6.0_33-b03-424.jdk/Contents/Home/

To redirect java to my 1.7 installation, I merely replace the old Home symlink with a new symlink pointing to the home directory of my Java 1.7 installation.

cd /Library/Java
mv Home Home-1.6
ln -s /Library/Java/JavaVirtualMachines/jdk1.7.0_21.jdk/Contents/Home/ Home

And voila! java -version shows that I am now running java 1.7. Just switch which symlink is currently named 'Home' to instantly change the default java JRE.

score 3 · Answer 7 · answered Nov 12 '13 at 10:15

Here is a easy way to switch java 6 and java 7 on mac osx.

step 1 : download jdk 7 from oracle official website http://www.oracle.com/technetwork/java/javase/downloads/jdk7-downloads-1880260.html and install it step by step follow the tips.

step 2: set $JAVA_HOME in .bash_profile

$ vim .bash_profile 

export JAVA_HOME=$(/usr/libexec/java_home)

$ source .bash_profile

$ echo $JAVA_HOME
/Library/Java/JavaVirtualMachines/1.7.0.jdk/Contents/Home

step 3: if you want to use jdk 6, just alternative $JAVA_HOME to jdk 6 home path

$ vim .bash_profile 

export JAVA_HOME=$(/usr/libexec/java_home -v 1.6)

$ source .bash_profile

$ echo $JAVA_HOME
/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home

score 3 · Answer 8 · answered Jun 10 '14 at 17:02

3

Manage your Java Environment (on Mac and Linux): http://www.jenv.be/

Similar to RVM for Ruby and N for Node but for Java.

answered Jun 10 '14 at 17:02

Misha Reyzlin

131
3

Phil · Answer 9 · 2014-02-21T14:39:16.783

Based on the above and a bit of other research, I've devised a script you can "source" (or "dot") into your profile. It'll prompt you with a menu of available JAVA_HOMEs on your Mac, though you can also specify the default home, or pre-select a menu choice.

In my .bash_profile:

export PREJAVA_PATH="$PATH:~/bin"
export PATH="${PREJAVA_PATH}"
. gojava -d

Note it requires a variable PREJAVA_PATH. You can also call it from the command line:

$ . gojava

Or to pre-choose the second option:

$ . gojava -c 2

File gojava is:

#!/bin/bash

_exe=/usr/libexec/java_home
_defaultHome=$($_exe)

usage() {
cat <<EOF
$0 [-d] [-c menu_choice]

Sets JAVA_HOME and PATH variables based on a user choice from a menu of available JDKs.

Parameters:

  -d : use system default ($_defaultHome)
  -c : specify a menu choice in advance, without being prompted

Note that environment variable PREJAVA_PATH must be set, and should include the PATH that 
you want with everything but JAVA_HOME/bin.

EOF
exit 1
}

setHomePath() {
  export JAVA_HOME="$1"
  export PATH="${JAVA_HOME}/bin":"${PREPATH}"
}

# TODO: [enhancement] figure out a better way to determine a PATH that excludes the JAVA_HOME
if [ -z "${PREJAVA_PATH}" ]; then
  usage  
else
  PREPATH=${PREJAVA_PATH}
fi

_default=0
_choice=0
OPTIND=1
while getopts "dc:" name; do
 case $name in
      d) _default=1 ;;
      c) _choice="$OPTARG" ;;
      *) echo "unknown parameter $name"
         usage
         ;;
 esac
done

if [ $_default -eq 1 ]; then
  setHomePath "$_defaultHome"
else
  i=1
  while read -r line; do
    choiceList[$i]="$line"
    homeList[$i]=$(echo $line | sed 's/[^\/]*\(\/.*\)/\1/')
    i=$(($i+1))
  done < <($_exe -V 2>&1 | egrep -v '^$|^\/|^Matching')

  if [ $_choice -gt 0 -a $_choice -lt $i ]; then
    setHomePath "${homeList[$_choice]}"
  else
    printf "\nList of available Java versions:\n"
    select choice in "${choiceList[@]}"; do
      if [ $REPLY -gt 0 -a $REPLY -lt $i ]; then
        setHomePath "${homeList[$REPLY]}"
        break
      fi
    done
  fi
fi

score 0 · Answer 10 · answered Mar 12 '16 at 13:10

The Fish shell version of @alex answer (add to ~/config/fish/config.fish):

alias java_ls '/usr/libexec/java_home -V 2>&1 | grep -E "\d.\d.\d[,_]" | cut -d , -f 1 | colrm 1 4 | grep -v Home'

function java_use
    set JAVA_HOME (/usr/libexec/java_home -v $argv)
    set PATH $JAVA_HOME/bin $PATH
    java -version
end

How do I switch between Java 7 and Java 6 on OS X 10.8.2?

10 Answers10

I don't think it's possible to switch JRE (runtime environments) see here:

Workaround:

To use another JDK see here: