In Java:

Consider a shared counter whose values are non-negative integers, initially zero. A time-printing thread increments the counter by one and prints its value each second from the start of execution. A message-printing thread prints a message every fifteen seconds. Have the message-printing thread be notified by the time-printing thread as each second passes by. Add another message-printing thread that prints a different message every seven seconds. Such addition must be done without modifying the time-printing thread implementation.

Have all involved threads share the counter object that is updated by the time-printing thread every second. The time-printing thread will notify other threads to read the counter object each time it updates the counter, then each message-printing thread will read the counter value and see if its assigned time period has elapsed; if so, it will print its message.

Write a Main2 class that contains the main method that tests your implementation. The output should look as follows:

1 2 3 4 5 6

7 second message

7 8 9 10 11 12 13

7 second message

14

15 second message

15 16 17 18 19 20

7 second message

21 22 23 24 . . .