The problem will be triggered when a non-member customer does checkout procedure. It will return a null pointer exception in the console and the program will halt. ================================================================================== Please input your Worker ID for logging in the system... 1 Please input your Member ID for logging in the system... 0 ---Welcome to Morx Supermarket--- ---To continue, please proceed your actions--- Input (1) for accessing Inventory System Input (2) for accessing Checkout System Input (3) for accessing Sales System Input (4) for accessing Membership System Input (5) for switching member Input (6) to exit 2 ---Welcome to Checkout System, ON9.--- Input commands for further management: Input (1) for Checkout Input (2) for refund Input (3) for exit 1 No Description Quantity Price($) 1 Coke 200 2000.0 2 Salt 50 1000.0 Please input (0) for proceed to checkout Please input (1) for remove products Please input (2) for modify quantities of products Please input (3) to cancel the checkout process 0 The total amount is: $3000.00 Please Input the amount of dollars that the customers paid 3100 Total changes is $100.00
The problem has been solved by the same method of bug603. ================================================================================== public void removeCartAfterTransaction(Member member) { member.getCart().clear(); } ================================================================================== Please input your Worker ID for logging in the system... 1 Please input your Member ID for logging in the system... 0 ---Welcome to Morx Supermarket--- ---To continue, please proceed your actions--- Input (1) for accessing Inventory System Input (2) for accessing Checkout System Input (3) for accessing Sales System Input (4) for accessing Membership System Input (5) for switching member Input (6) to exit 2 ---Welcome to Checkout System, ON9.--- Input commands for further management: Input (1) for Checkout Input (2) for refund Input (3) for exit 1 No Description Quantity Price($) 1 Coke 200 2000.0 2 Salt 50 1000.0 Please input (0) for proceed to checkout Please input (1) for remove products Please input (2) for modify quantities of products Please input (3) to cancel the checkout process 0 The total amount is: $3000.00 Please Input the amount of dollars that the customers paid 3000 Total changes is $0.00 Input commands for further management: Input (1) for Checkout Input (2) for refund Input (3) for exit