:~$ sudo apt-get purge oracle-java7-installer
[sudo] password for computer:
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages were automatically installed and are no longer required:
  g++ g++-5 libalgorithm-diff-perl libalgorithm-diff-xs-perl
  libalgorithm-merge-perl libstdc++-5-dev
Use 'sudo apt autoremove' to remove them.
The following packages will be REMOVED:
  oracle-java7-installer*
0 upgraded, 0 newly installed, 1 to remove and 137 not upgraded.
1 not fully installed or removed.
After this operation, 127 kB disk space will be freed.
Do you want to continue? [Y/n] y
(Reading database ... 176078 files and directories currently installed.)
Removing oracle-java7-installer (7u80+7u60arm-0~webupd8~1) ...
Purging configuration files for oracle-java7-installer (7u80+7u60arm-0~webupd8~1) ...
Processing triggers for shared-mime-info (1.5-2ubuntu0.1) ...
Processing triggers for gnome-menus (3.13.3-6ubuntu3.1) ...
Processing triggers for desktop-file-utils (0.22-1ubuntu5) ...
Processing triggers for bamfdaemon (0.5.3~bzr0+16.04.20160701-0ubuntu1) ...
Rebuilding /usr/share/applications/bamf-2.index...
Processing triggers for mime-support (3.59ubuntu1) ...