I made a very simple test from the command line, and I think I found a way to do that (without large changes in the code, just on the Alarms Controller): First unacknowledged the alarm, then acknowledge again. If that operation is done by the user interested to steal the alarm, the operation is done.

Suppose that exists an alarm with ID=100 which is owned by user1, and user2 want to steal the alarm. The user2 could do this from command line:

To unacknowledged from user1:
curl -d 'actionCode=unack&alarm=251' http://user2:xxxx@localhost:8980/opennms/alarm/acknowledge

To re-acknowledged as user2:
curl -d 'actionCode=ack&alarm=251' http://user2:xxxx@localhost:8980/opennms/alarm/acknowledge

So the change in the code could be just add a new action code called "steal", and the code will look like this:

...
} else if (action.equals("steal")) {
m_webAlarmRepository.unacknowledgeAlarms(alarmIds, request.getRemoteUser());
m_webAlarmRepository.acknowledgeAlarms(alarmIds, request.getRemoteUser(), new Date());
} else {
throw new ServletException("Unknown acknowledge action: " + action);
}

An improvement could be to put the steal processing inside WebAlarmRepository, in order to validate that the alarm should be already acknowledged and owned by a different user.

Thoughs ?

If I understood correctly, the idea is, when a user is looking at the acknowledged alarms, and the user is interested on a particular alarm, it could be useful to include a "Steal Button" at the Alarms Details Page, to let the user change the ownership of the alarm with their current login name.

Is that right ?

Of course the "Steal Button" will be showed only for acknowledged alarms where the current user is different from the user who acknowledged the alarm in the first place.