Written before, please refer to:
public void submenu() {
menu();
int n = sc .nextInt();
while (n != 0) {
switch (n) {
case 1:
addDvd ("D:/dvd.txt");
break;
case 2:
deleteDvd("D:/dvd.txt");< /p>
break;
case 3:
queryDvd("D:/dvd.txt");
break;
default:
break;
}
menu();
n = sc.nextInt();
p>}
}
private void menu() {
System.out.println("Enter dvd management interface");
p>System.out.println("1. Add dvd");
System.out.println("2. Delete dvd");
System.out .println("3. Search dvd");
System.out.println("Please select an operation, ending with 0:");
}