How to Enable Java plugin support on Firefox on Linux

Many web pages use Java applets for interactive content such as online games, WebEx (Online meeting), etc.,. By default all the browsers disabled the plugin due to security issue and still you want to enable to access the trusted web sites. We can enable it on browser by following below procedures. Make sure you system should have installed Oracle JAVA before proceeding to enable the JAVA Applet.

Method 1 : Enable Java plugin Support on Firefox through Oracle Java

1) Install Oracle Java

Make sure you system should have installed Oracle JAVA before proceeding to enable the JAVA Applet.

# java -version
java version "1.8.0_74"
Java(TM) SE Runtime Environment (build 1.8.0_74-b02)
Java HotSpot(TM) 64-Bit Server VM (build 25.74-b02, mixed mode)

2) Locate Firefox

First we need to locate the Firefox installation location to create plugin directory.

# whereis firefox
firefox: /usr/bin/firefox /usr/lib/firefox /etc/firefox /usr/share/man/man1/firefox.1.gz

3) Enable Java applet on Firefox

Navigate to Menu >> Add-ons >> Plugins >> Oracle JAVA, Search Java(TM) Platform, If Java is disabled, click on Never Activate to open its drop-down menu and select the option to activate Java. The recommended (default) option is Ask to Activate, which lets you run Java when prompted.

4) Create symbolic link to enable Java in Firefox

If you didn’t find Java(TM) Platform plugin, use the below method to enable it.

[Check Java installed location]
# update-alternatives --config java
There are 3 choices for the alternative java (providing /usr/bin/java).

  Selection    Path                                            Priority   Status
------------------------------------------------------------
  0            /usr/lib/jvm/java-8-oracle/jre/bin/java          1072      auto mode
  1            /usr/lib/jvm/java-6-openjdk-amd64/jre/bin/java   1061      manual mode
  2            /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java   1071      manual mode
* 3            /usr/lib/jvm/java-8-oracle/jre/bin/java          1072      manual mode

Press  to keep the current choice[*], or type selection number:

[Create a directory called plugins if you do not have it]
# mkdir -p /usr/lib/firefox-addons/plugins

[Navigate to Plugins directory]
# cd /usr/lib/firefox-addons/plugins

[Create a symbolic link]
# ln -s /usr/lib/jvm/java-8-oracle/jre/lib/amd64/libnpjp2.so

Restart the Firefox browser and verify.

Method 2 : Enable Java plugin Support on Firefox through Oracle Java

1) Install OpenJDK

Simply fire the below commands to install openJDK & Java plugin support on firefox.

[Install openJRE]
$ sudo apt-get install openjdk-8-jre

[Install Java Plugin]
$ sudo apt-get install icedtea-8-plugin

Enjoy…)