How to specify Eclipse's java.home setting for Ivy/Ant

When running an ivy resolve via IvyDE in Eclipse, which contains a packager.xml that executes a javac ant task, I get the following:

Unable to find a javac compiler; com.sun.tools.javac.Main is not on the classpath. Perhaps JAVA_HOME does not point to the JDK. It is currently set to "C:\Program Fil开发者_如何学运维es\Java\jdk1.6.0_22\jre" at org.apache.tools.ant.taskdefs.compilers.CompilerAdapterFactory.getCompiler(CompilerAdapterFactory.java:108)

In eclipse.ini I have

-vm
C:\Program Files\Java\jdk1.6.0_22\bin\javaw.exe

and in Help - About Eclipse - Installation Details - Configuration I see

java.home=C:\Program Files\Java\jdk1.6.0_22\jre

How can I make java.home point to C:\Program Files\Java\jdk1.6.0_22 instead?

Eclipse uses its own javac implementation internally. Therefore for most of the purpose you just need a compatible JRE. But javac task in ANT considers the JAVA_HOME or check for the local path variable. On windows machine as temporary fix you can do:

Open a command prompt then type SET path=C:\Program Files\Java\jdk1.6.0_22\;%path% hit enter then type <eclipsehome>\eclipse.exe

Now any process spawned from your eclipse will have your JDK version in the path variable.

for a permanent solution.. 1. go to advance system setting 2. select advanced tab 3. select environment variables 4. modify the system path variable and JAVA_HOME (if required)

You can do the similar thing for *nix system (just check how to set environment setting on them)

Hope this will work.

UPDATE

The PROJECT classpath isn't the same as the ANT classpath. To set up an Ant classpath, navigate to window->preferences->ant->runtime here check whether the Global Entries points to C:\Program Files\Java\jdk1.6.0_22\lib\tools.jar if not then add it. Normally it works in most of the cases where ant cries for javac task. if it fails then please check whether some other script is not resetting your JAVA_HOME variable and ANT global entries setting.

If IvyDE is not using the ANT bundled with eclipse as plugin (and referring to some standard installation) or if you have defined a environment variable like ANT_HOME then copy tools.jar file from C:\Program Files\Java\jdk1.6.0_22\lib\ to ANT_HOME\lib.

Also check this previous SO post ( Ant can't find Javac. No matter what I do it always claims JAVA_HOME is "C:\Program Files\Java\jre6" )

UPDATE 2 ok.. Check this page... http://ant.apache.org/ivy/ivyde/history/latest-milestone/preferences.html

Order of the classpath entries: By default, the classpath container entries are ordered by order of declaration in the ivy.xml. When there are many entries, it can be useful to have them ordered lexically for enhanced readability.

Is tools.jar present in ivy.xml? please check once.