Enable JDK 7 in Eclipse Indigo on Mountain Lion

Question

I'm working on a Scala Project with Eclipse (Indigo SR2). Today I updated my machine to Mountain Lion because we need some functionality of JDK 7. Installing JDK 7 worked fine:

$ java -version
java version "1.7.0_13"
Java(TM) SE Runtime Environment (build 1.7.0_13-b20)
Java HotSpot(TM) 64-Bit Server VM (build 23.7-b01, mixed mode)

In Eclipse I changed the following settings:

• Java => Compiler => Installed JREs: Adding JDK1.7.0 with path /Library/Java/JavaVirtualMachines/jdk1.7.0_13.jdk/Contents/Home
• Java => Compiler => Installed JREs => Exucution Environment: Set JavaSE-1.7 to JDK1.7.0
• Java => Compiler: Compliance Level: 1.7
• Scala => Compiler: Target = jvm-1.7

Then I restarted Eclipse and tried to run a script. However, I always get the error:

value getPlatformMXBean is not a member of object java.lang.management.ManagementFactory

Said method is only available as of Java 1.7 and Eclipse does not seem to find it although command-clicking on it reveals the function in the class ManagementFactory. About Eclipse => Configuration shows that it is still using JDK 6 (java.runtime.version=1.6.0_37-b06-434-11M3909), but I need JDK 7.

So I tried the following (as also described on StackOverflow and other sites):

• add -vm /Library/Java/JavaVirtualMachines/jdk1.7.0_13.jdk/Contents/Home/bin/java to the eclipse.ini file (double checked the path, the proper location in the file according to the eclipse website, and also added the newline in between)
• add the same to the Info.plist
• $ /Applications/eclipse/Eclipse.app/Contents/MacOS/eclipse -vm /Library/Java/JavaVirtualMachines/jdk1.7.0_13.jdk/Contents/Home/
• Create a symbolic link from 1.6 to 1.7

But no luck, Eclipse keeps starting with only JDK-6. What is strange is that I can explicitly change the JRE in Run=>Run Configurations to JDK7 and it will run it that way. But I would not want to change that for every single runnable file.

Any further suggestions?

---

Thanks to the hint from EECOLOR, I was able to use the Scala plugin in Eclipse Juno, where the JDK7 runs just fine. However, now I run into what appears to be a dependency issue. The exception I get can be seen here: https://gist.github.com/anonymous/ac0f3a3655419e5149fa

Strangly, the file just starts fine when I run it from the command line with a simple java -cp JARFILE com.AND-SO-ON.file. For building the sources and getting the dependencies, we use SBT.

My Eclipse.ini looks as follows (default except for the Xmx):

-startup
../../../plugins/org.eclipse.equinox.launcher_1.3.0.v20120522-1813.jar
--launcher.library
../../../plugins/org.eclipse.equinox.launcher.cocoa.macosx.x86_64_1.1.200.v20120522-1813
-product
org.eclipse.epp.package.java.product
--launcher.defaultAction
openFile
-showsplash
org.eclipse.platform
--launcher.XXMaxPermSize
256m
--launcher.defaultAction
openFile
-vmargs
-Dosgi.requiredJavaVersion=1.5
-Dhelp.lucene.tokenizer=standard
-XstartOnFirstThread
-Dorg.eclipse.swt.internal.carbon.smallFonts
-XX:MaxPermSize=256m
-Xms40m
-Xmx1060m
-Xdock:icon=../Resources/Eclipse.icns
-XstartOnFirstThread
-Dorg.eclipse.swt.internal.carbon.smallFonts

The same project (i.e. really the same project, not just the same code) runs without dependency problems in Eclipse Indigo. Edit: Just found out, that this exception is caused by JDK7 and not the Eclipse version used.

Answer 1

I am using the preview version that supports Juno just fine: http://scala-ide.org/download/milestone.html#scala_ide_21_milestone_3

Answer 2

In the meantime, I managed to solve these problems.

First try:

• Update to the most current JDK (1.7.0u15 at the moment)
• Clone the code from Github again
• Install Eclipse Indigo
  • reinstalling Eclipse solved the problems with JDK6, it now just starts with JDK7 without any further configuration
• Install the Scala plugin
• create a new Eclipse project using sbt eclipse
• import the created project

Oops, does not work! I still get this exception:

value getPlatformMXBean is not a member of object java.lang.management.ManagementFactory

... which is strange because Eclipse now really runs with the JDK7. Without digging any deeper, I just gave Eclipse Juno a shot.

Second Try:

• Do all the same as above
• Install Eclipse Juno instead of Indigo
• Yay, it works! :)

Conclusion:

So I am not sure why, but Eclipse Indigo somehow does not like getPlatformMXBean. It does not appear to be an issue with the JDK but Eclipse itself.