How can I open Java's Control Panel to change the security settings?
- Open a terminal
- Execute the command:
as of java9... (Oct 2017)
This assumes you have installed java9 yourself (since the webupd8 PPA method is currently broken). After repeated purging of all things java-related (especially the default-installed java), I've not taken the time to fix the "update alternatives" infrastructure, so that particular link to jcontrol is borked (that is, the answer above -- "just type jcontrol in a terminal window" -- does not work).
This also assumes you have a working java installation (java -version returns something).
# ls -al `which java`
You'll get something back like this:
lrwxrwxrwx ... /usr/bin/java -> /usr/java/default/bin/java
So your command will be:
Now, you can fix the alternatives link (the quick-and-dirty way), so you can just type jcontrol and have it work. I do recommend you use the update-alternatives structures (be sure you know what you are doing before taking these steps. I suggest using ls -al to check the links). This is done as root. You can put sudo in front of the commands if you feel better about doing that.
# ln -s -f /usr/java/default/bin/jcontrol /etc/alternatives/jcontrol # ln -s -f /etc/alternatives/jcontrol /usr/bin/jcontrol