Using java in FC1(with eclipse)-help needed

[Kaustubh Ghosh]

On Wednesday 17 March 2004 12:53 am, Mario St-Gelais wrote:
> Kaustubh Ghosh wrote:
> >I am quite novice towards java programming in linux.To start with I
> > installed j2re1.4.2_03 and also j2sdk1.4.2_04 in FC1(Both from
> > java.sin.com).Now peculiar problems arise.
> >When I type "java -version" it gives 1.3.1(
> >When I type "/usr/java/j2sdk1.4.2_04/bin/java -version" it gives 1.4.2_04.
> >Anyway  I  can compile any .java  file with javac.
> >But when I try to run it with java(any of the above) the gui would not
> >come.(Hello World executes perfectly with System.out.println as also other
> >non-gui programs).
> >
> >I also installed eclipse sdk.It created a directory "eclipse" under
> > /opt.When I cycled to the directory and typed "eclipse" I got messages
> >"
> >warning:cannot determine -os type
> >warning:cannot determine -ws type.
> >warning:cannot determine -arch type.
> >warning:cannot determine -showsplash type.
> >"
> >After a while it gives an error(in a gui):
> >"Error:Java (VM) had to be shut down:Exit Code=1
> >/usr/bin/java
> >-cp /opt/eclipse/startup.jar org.eclipse.core.launcher.Main
> >-os linux
> >-ws gtk
> >-arch x86
> >-showsplash /opt/eclipse/eclipse_showsplash 600
> >"
> >
> >Cannot make any head or tail of it.
> >I also tried to install Netbeans developer using "nbdx2_21.class" file by
> >giving command "java nbdx2_21".What I got was:
> >"Exception in thread "main" java.lang.NoClassDefFoundError: nbdx2_21"
> >
> >Can I get any help?Thanks in advance.
>
> You might have 2 versions of java installed...  Have you set environment
> variables? (JAVA_HOME).  What do you get when you do "echo $JAVA_HOME"?
> Also, note that when you install j2sdk, jre comes with it.  But I dont't
> think that this is the problem.
>
> For the second part, not sure...


When I isuue the command $JAVA_HOME I get nothing.(just a blank line).
How can I set the environment variables?Consider me a novice.Thanks.