Nov 8, 2018

How to get java plugin to work with Firefox on Linux

Acording to the Firefox developer documentation plugins live here:
  • Directory pointed to by MOZ_PLUGIN_PATH environment variable
  • ~/.mozilla/plugins
  • /usr/lib/mozilla/plugins (on 64-bit systems, /usr/lib64/mozilla/plugins is used instead)
  • Plug-ins within toolkit bundles
  • [Profile directory]/plugins, where [Profile directory] is a user profile directory
Link libnpjp2.so of your java installation to your mozilla plugins directory, for example: 

cd /usr/lib64/mozilla/plugins
ln -s /usr/java/latest/lib/amd64/libnpjp2.so

It is disabled by default. You have to manually enable it in your browsers.  

Also only install the latest version from java.com, not the latest version from oracle.com.  Latest version from oracle.com sometimes is more advanced for development and if it is different from the latest version of java.com, you may still be asked to install java for your browser.