Installing Java in Slackware
 

I have sucessfully installed java in Slackware. The output of whereis java is:
java: /usr/lib/java /usr/share/java

but Mozilla firefox doesn't show java in its plugins. Is it that I have to maually configure Firefox to link it with java?

Also output of java -version says that:
java: command not found

I remember doing this a while back and had to log in and back out again in order to load the java profile when I installed OpenJDK. You don't make mention on which version you tried to install? You may also have to restart though, according to the Slackware doc online.

If I remember correctly the Slackbuild for Java deliberately disables the java plugin because of security concerns. If you pass EXPLOIT_ME=YES to the Slackbuild, it should build the Mozilla plugins.