在Mac OS Mavericks上一起维护Java 6和Java 7

Question

There have been various posts in several places about how hard it is it deal with Java on the mac. I had installed Java 7 some time ago on my mac with os mavericks, but then found that certain software ( like Open Office) can't run without Java 6, so after a lot of work I rolled that back. Now I would like to use pydev with Eclipse. However this software requires Java 7. How do I maintain both versions of Java on the same machine?

Thanks

Answer 1

Maintaining different versions of Java on a Mac is straight forward.

• Java 6 and earlier were developed and maintained by Apple
• Java 7 and later are developed and maintained by Oracle

You already have Java 6 installed, presumably from somewhere like Java for Mac OS X 10.6 Update 17 .

For all versions of Java after 6.x you must go to the Oracle download site , where both Java 7 and 8 can be found.

Multiple versions of Java can coexist on a Mac. You can find out what you already have installed by using the

/usr/libexec/java_home -V

command in Terminal. For example:

[steve@Steves-MacBook-Pro-2 ~]$ /usr/libexec/java_home -V
Matching Java Virtual Machines (28):
    1.8.0, x86_64:  "Java SE 8" /Library/Java/JavaVirtualMachines/jdk1.8.0.jdk/Contents/Home
    1.7.0_51, x86_64:   "Java SE 7" /Library/Java/JavaVirtualMachines/jdk1.7.0_51.jdk/Contents/Home
    1.7.0_45, x86_64:   "Java SE 7" /Library/Java/JavaVirtualMachines/jdk1.7.0_45.jdk/Contents/Home
    1.7.0_40, x86_64:   "Java SE 7" /Library/Java/JavaVirtualMachines/jdk1.7.0_40.jdk/Contents/Home
    1.7.0_25, x86_64:   "Java SE 7" /Library/Java/JavaVirtualMachines/jdk1.7.0_25.jdk/Contents/Home
    1.7.0_21, x86_64:   "Java SE 7" /Library/Java/JavaVirtualMachines/jdk1.7.0_21.jdk/Contents/Home
    1.7.0_17, x86_64:   "Java SE 7" /Library/Java/JavaVirtualMachines/jdk1.7.0_17.jdk/Contents/Home
    1.7.0_15, x86_64:   "Java SE 7" /Library/Java/JavaVirtualMachines/jdk1.7.0_15.jdk/Contents/Home
    1.7.0_13, x86_64:   "Java SE 7" /Library/Java/JavaVirtualMachines/jdk1.7.0_13.jdk/Contents/Home
    1.7.0_11, x86_64:   "Java SE 7" /Library/Java/JavaVirtualMachines/jdk1.7.0_11.jdk/Contents/Home
    1.7.0_10, x86_64:   "Java SE 7" /Library/Java/JavaVirtualMachines/jdk1.7.0_10.jdk/Contents/Home
    1.7.0_07, x86_64:   "Java SE 7" /Library/Java/JavaVirtualMachines/jdk1.7.0_07.jdk/Contents/Home
    1.7.0_06, x86_64:   "Java SE 7" /Library/Java/JavaVirtualMachines/jdk1.7.0_06.jdk/Contents/Home
    1.7.0_04, x86_64:   "Java SE 7" /Library/Java/JavaVirtualMachines/1.7.0.jdk/Contents/Home
    1.6.0_65-b14-462, x86_64:   "Java SE 6" /Library/Java/JavaVirtualMachines/1.6.0_65-b14-462.jdk/Contents/Home
    1.6.0_65-b14-462, i386: "Java SE 6" /Library/Java/JavaVirtualMachines/1.6.0_65-b14-462.jdk/Contents/Home
    1.6.0_51-b11-457, x86_64:   "Java SE 6" /Library/Java/JavaVirtualMachines/1.6.0_51-b11-457.jdk/Contents/Home
    1.6.0_51-b11-457, i386: "Java SE 6" /Library/Java/JavaVirtualMachines/1.6.0_51-b11-457.jdk/Contents/Home
    1.6.0_45-b06-451, x86_64:   "Java SE 6" /Library/Java/JavaVirtualMachines/1.6.0_45-b06-451.jdk/Contents/Home
    1.6.0_45-b06-451, i386: "Java SE 6" /Library/Java/JavaVirtualMachines/1.6.0_45-b06-451.jdk/Contents/Home
    1.6.0_35-b10-428, x86_64:   "Java SE 6" /Library/Java/JavaVirtualMachines/1.6.0_35-b10-428.jdk/Contents/Home
    1.6.0_35-b10-428, i386: "Java SE 6" /Library/Java/JavaVirtualMachines/1.6.0_35-b10-428.jdk/Contents/Home
    1.6.0_33-b03-424, x86_64:   "Java SE 6" /Library/Java/JavaVirtualMachines/1.6.0_33-b03-424.jdk/Contents/Home
    1.6.0_33-b03-424, i386: "Java SE 6" /Library/Java/JavaVirtualMachines/1.6.0_33-b03-424.jdk/Contents/Home
    1.6.0_32-b05-420, x86_64:   "Java SE 6" /Library/Java/JavaVirtualMachines/1.6.0_32-b05-420.jdk/Contents/Home
    1.6.0_32-b05-420, i386: "Java SE 6" /Library/Java/JavaVirtualMachines/1.6.0_32-b05-420.jdk/Contents/Home
    1.6.0_31-b04-415, x86_64:   "Java SE 6" /Library/Java/JavaVirtualMachines/1.6.0_31-b04-415.jdk/Contents/Home
    1.6.0_31-b04-415, i386: "Java SE 6" /Library/Java/JavaVirtualMachines/1.6.0_31-b04-415.jdk/Contents/Home

Double clickable applications on the Mac specify which versions of Java to use in their info.plist resources.

If you're running apps from the command line you use the same /usr/libexec/java_home command as above:

[steve@Steves-MacBook-Pro-2 ~]$ export JAVA_HOME=$(/usr/libexec/java_home -v1.8)
[steve@Steves-MacBook-Pro-2 ~]$ java -version
java version "1.8.0"
Java(TM) SE Runtime Environment (build 1.8.0-b132)
Java HotSpot(TM) 64-Bit Server VM (build 25.0-b70, mixed mode)