[CentOS] Installing java on CentOS 5

strugging with things here...

tried tracking the info on the Wiki (which apparently is now in need of
a maintainer)...
http://wiki.centos.org/HowTos/JavaOnCentOS

My primary interest is using Xalan/Saxon/xslt/xsl-fo docbook generation.

I was thinking that all I really need is jre but downloaded both jre and
jdk just in case.

can anyone tell me what I'm doing wrong? (after removing both jdk &
jre)...

-rw-r--r-- 1 root    root    56835774 Sep 25 00:47
jdk-6u3-linux-i586.rpm
-rw-r--r-- 1 root    root    18835725 Sep 25 00:45
jre-6u3-linux-i586.rpm

I tried installing each of them but they never show up in
# alternatives --config java

# rpm -qa|grep jpackage
jpackage-utils-1.7.3-1jpp.2.el5

# rpm -ivh jre-6u3-linux-i586.rpm
Preparing...                ###########################################
[100%]
   1:jre                    ###########################################
[100%]
Unpacking JAR files...
        rt.jar...
        jsse.jar...
        charsets.jar...
        localedata.jar...
        plugin.jar...
        javaws.jar...
        deploy.jar...

# alternatives --config java

There is 1 program that provides 'java'.

  Selection    Command
-----------------------------------------------
*+ 1           /usr/lib/jvm/jre-1.4.2-gcj/bin/java

Enter to keep the current selection[+], or type selection number:

Craig