Problem w/ setting Sun's JVM via (g)alternatives?

[Daniel B. Thurman]

Since I am trying to get Eclipse's Ganemede working
again, I am told that I would need to use Sun's JRE,
however, I opted to use the JDK instead of the JRE.

I have downloaded and installed Sun's JDK 1.6 & 1.5
into /opt and it looks good.  I can via environment
setting run the java -version tests.

However

I have added the /opt/jdk[...]/bin/java to the alternatives
list in the 'java' category for both versions as follows:

/opt/jdk.1.6[...]/bin/java   priority: 1000
/opt/jdk.1.5[...]/bin/java   priority: 500

then selected JDK v1.6, and tried to launch Eclipse.

What resulted was a popup failure with the
relevant entry:

[...]
-vm /opt/jdk1.6.0_16/bin/../jre/lib/i386/client/libjvm.so
[...]
Note: the entire "barf" is at the end of the line.

Why is 'java' replaced with '../jre/lib/i386/client/libjvm.so'?
Yes, the -vm path exist.

Is this normal?

Side question: is the JRE instead of JDK required?  I wanted
the JDK so that I can do Java development but I do not think
there is a difference except only where the jre path is different.

Thanks-
Dan

The "barf":
===========================================
JVM terminated. Exit code=-1
-Xms40m
-Xmx512m
-XX:MaxPermSize=128m
-XX:CompileCommand=exclude,org/eclipse/core/internal/dtree/DataTreeNode,forwardDeltaWith
-XX:CompileCommand=exclude,org/eclipse/jdt/internal/compiler/lookup/ParameterizedMethodBinding,<init>
-XX:CompileCommand=exclude,org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/CPPTemplates,instantiateTemplate
-XX:CompileCommand=exclude,org/eclipse/cdt/internal/core/pdom/dom/cpp/PDOMCPPLinkage,addBinding
-XX:CompileCommand=exclude,org/python/pydev/editor/codecompletion/revisited/PythonPathHelper,isValidSourceFile
-XX:CompileCommand=exclude,org/python/pydev/ui/filetypes/FileTypesPreferencesPage,getDottedValidSourceFiles
-Dorg.eclipse.equinox.p2.reconciler.dropins.directory=/usr/share/eclipse/dropins
-Djava.class.path=/usr/lib/eclipse/plugins/org.eclipse.equinox.launcher_1.0.101.R34x_v20081125.jar
-os linux
-ws gtk
-arch x86
-showsplash 
/usr/lib/eclipse//plugins/org.fedoraproject.ide.platform_3.4.2/splash.bmp
-launcher /usr/lib/eclipse/eclipse
-name Eclipse
--launcher.library 
/usr/lib/eclipse/plugins/org.eclipse.equinox.launcher.gtk.linux.x86_1.0.101.R34x_v20080805/eclipse_1116.so
-startup 
/usr/lib/eclipse/plugins/org.eclipse.equinox.launcher_1.0.101.R34x_v20081125.jar
-vm /opt/jdk1.6.0_16/bin/../jre/lib/i386/client/libjvm.so
-vmargs
-Xms40m
-Xmx512m
-XX:MaxPermSize=128m
-XX:CompileCommand=exclude,org/eclipse/core/internal/dtree/DataTreeNode,forwardDeltaWith
-XX:CompileCommand=exclude,org/eclipse/jdt/internal/compiler/lookup/ParameterizedMethodBinding,<init>
-XX:CompileCommand=exclude,org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/CPPTemplates,instantiateTemplate
-XX:CompileCommand=exclude,org/eclipse/cdt/internal/core/pdom/dom/cpp/PDOMCPPLinkage,addBinding
-XX:CompileCommand=exclude,org/python/pydev/editor/codecompletion/revisited/PythonPathHelper,isValidSourceFile
-XX:CompileCommand=exclude,org/python/pydev/ui/filetypes/FileTypesPreferencesPage,getDottedValidSourceFiles
-Dorg.eclipse.equinox.p2.reconciler.dropins.directory=/usr/share/eclipse/dropins
-Djava.class.path=/usr/lib/eclipse/plugins/org.eclipse.equinox.launcher_1.0.101.R34x_v20081125.jar 

===========================================