sudo update-alternatives --config java
command it shows only one choice available.java
binary. This however, isn't enough to execute Java web applets on your browser, which can be accomplished by installing the Icedtea plugin:about:addons
, in the plugin section, check if the plugin is enabled. Mozilla disables insecure plugins by default, that means that Java is disable even after installation due security concerns. You need to activate it before using it.