Need help with Java console program.

Employee ID generator.

The user will be asked to choose for what group will work. 1) Sales 2) Research 3) Production

The program will generate a 7-digit random number.

Based on user selection a 3-character prefix will be added to the random number:

For Sales the prefix will be SAL (example of number SAL1234567)

For Research the prefix will be RES (example of number RES1234567)

For Production the prefix will be PRO (example of number PRO1234567)

This IDs need to be recorded in a txt file. But before the ID is recorded needs to check the txt file to see if the ID is issued before (No duplicates).

IF ID matches the IDs in the txt file it should not be recorded, and a new random number should be issued.

IF ID does not match the IDs in txt file then it should go ahead and record the ID in the txt file.

The new issued ID should be displayed in console (example: Your employee ID is PRO7654321)

Thanks