Why can't I select the Sun Java VM ?

[Linuxguy123]

On Sun, 2008-11-30 at 14:06 -0300, Marcelo Magno T. Sales wrote:
> Em Dom 30 Nov 2008, Linuxguy123 escreveu:
> > # alternatives --config java
> >
> > There are 2 programs which provide 'java'.
> >
> >   Selection    Command
> > -----------------------------------------------
> > *  1           /usr/lib/jvm/jre-1.6.0-openjdk/bin/java
> >  + 2           /usr/lib/jvm/jre-1.5.0-gcj/bin/java
> >
> > So it thinks I have 2 versions of Java.
> >
> > Here is the first:
> >
> > # java -version
> > java version "1.6.0_0"
> > IcedTea6 1.4 (6b12-Fedora-10) Runtime Environment (build 1.6.0_0-b12)
> > OpenJDK Server VM (build 10.0-b19, mixed mode)
> >
> > Here is the second:
> >
> > # java -version
> > java version "1.5.0"
> > gij (GNU libgcj) version 4.3.2 20081105 (Red Hat 4.3.2-7)
> >
> > However, I actually have 3 versions of Java, because I installed the
> > Sun Java from a Sun rpm:
> >
> > # rpm -ql jre
> > /usr/java/jre1.5.0_15/CHANGES
> > /usr/java/jre1.5.0_15/COPYRIGHT
> > /usr/java/jre1.5.0_15/LICENSE
> > /usr/java/jre1.5.0_15/README
> > /usr/java/jre1.5.0_15/THIRDPARTYLICENSEREADME.txt
> > /usr/java/jre1.5.0_15/Welcome.html
> > /usr/java/jre1.5.0_15/bin
> > /usr/java/jre1.5.0_15/bin/ControlPanel
> > /usr/java/jre1.5.0_15/bin/java
> >
> > If I test it it works fine.
> >
> > # /usr/java/jre1.5.0_15/bin/java -version
> > java version "1.5.0_15"
> > Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_15-b04)
> > Java HotSpot(TM) Server VM (build 1.5.0_15-b04, mixed mode)
> >
> > So I move it to /usr/lib/jvm and run again:
> >
> > alternatives --config java
> >
> > There are 2 programs which provide 'java'.
> >
> >   Selection    Command
> > -----------------------------------------------
> > *+ 1           /usr/lib/jvm/jre-1.6.0-openjdk/bin/java
> >    2           /usr/lib/jvm/jre-1.5.0-gcj/bin/java
> >
> > The Sun Java doesn't show up.
> >
> > /usr/lib/jvm looks like this:
> >
> > ls -al
> > total 204
> > drwxr-xr-x   5 root root   4096 .
> > drwxr-xr-x 183 root root 139264 ..
> > drwxr-xr-x   3 root root   4096 java-1.5.0-gcj-1.5.0.0
> > drwxr-xr-x   3 root root   4096 java-1.6.0-openjdk-1.6.0.0
> > lrwxrwxrwx   1 root root     21 jre -> /etc/alternatives/jre
> > lrwxrwxrwx   1 root root     27 jre-1.5.0 ->
> > /etc/alternatives/jre_1.5.0 drwxr-xr-x   7 root root   4096
> > jre1.5.0_15
> > lrwxrwxrwx   1 root root     26 jre-1.5.0-gcj ->
> > java-1.5.0-gcj-1.5.0.0/jre
> > lrwxrwxrwx   1 root root     27 jre-1.6.0 ->
> > /etc/alternatives/jre_1.6.0 lrwxrwxrwx   1 root root     30
> > jre-1.6.0-openjdk ->
> > java-1.6.0-openjdk-1.6.0.0/jre
> > lrwxrwxrwx   1 root root     25 jre-gcj -> /etc/alternatives/jre_gcj
> > lrwxrwxrwx   1 root root     29 jre-openjdk
> > -> /etc/alternatives/jre_openjdk
> >
> > How do I get the Sun java to be the default Java, without doing a 24
> > step build that Googling finds ?
> 
> You must register the new java alternative with the alternatives command 
> first. Just type in as root in a terminal window:
> alternatives --­­install /usr/bin/java java /opt/jre1.6.0/bin/java 3
> alternatives --config java

Thanks for the reply Marcelo.  


> And select the one you want to be the default. Replace 
> "/opt/jre1.6.0/bin/" with the path where you have decompressed Sun's 
> java binaries. 
> I've read a long time ago that we shouldn't install Sun's Java RPM in 
> Fedora, because it would overwrite some files of GCJ. 

Interesting.


> When you update 
> GCJ the next time, it will overwrite back the Sun's files. I don't know 
> for sure if this was correct or if it is still the case but maybe, just 
> to be safe, you should download the non-rpm package from Sun and 
> decompress it manually in /opt or other directory you like.
> If any one knows if it's still not recommended to install Sun's Java RPM 
> package, please let us know.

I wasn't aware of this.  Maybe it the problem with my Eclipse install.