how to record keystrokes in background using java? -

i going research on which key typed in hour in 24-hour-day? later, research on which word used in hour in 24-hour-day?

say in evening find used word or bye people ends meeting in evening.

so, need record keystrokes on background using java application time-stamp. questions are:

1. how run java program on background?(obviously informing user).
2. how record keystrokes used in other applications , counted in java application without affecting original application?

note that:

this question not serve problem. though has accepted answer, answer not helpful me because it not distinguish between uppercase , lowercase letter, returns same ascii character. gave sources , other files. expect more readable answer , clear view how java program launch on start , run on background.

just little information moving in right direction. looking implement listen keystrokes keylistener. believe actual function keytyped(actionevent e) not sure.

other run program silently in background require manipulation of window + windows properties. have program run without ui, or create lightweight ui posts data. if looking actual "out of sight out of mind" background process, not sure how java. imagine un-intrusive gui sufficient purposes.