1os is a very simple operating system that allows multiple users to save and print files. the 141os manages multiple disks, multiple printers, and multiple users - all of which can be considered concurrent processes. files can be stored on any disk and printed on any printer by any user. the goal of the system is to exploit possible parallelism to keep the devices (disks and printers) as busy as possible. this will be a two week assignment. the first part (due week 9) is to define the java classes for userthread, disk, and printer. the second part (due week 10) is to write printjobthread that manage printing a specified file and userthread that saves files to disk sectors. (note only one line of a file may be stored in a sector, so a file will require one sector per line.) although printers and disks can be thought of as parallel processes, i suggest you not make them threads. if you do, you must make them daemon threads by calling setdaemon or your program will never terminate.1. define symbolic constants for number_of_users=4, number_of_disks=2, and number_of_printers=3. store instances of the appropriate objects in three separate arrays: users, printers, and disks.2. a sample of the input (user*) and output (printer*) is in the hw8 directory located in my homework starts directory *** here ***. the printer* files will be generated by your program, but the exact files that get sent to each printer may vary. if you use a bufferedwriter, be sure you flush the buffer after each write.