Question

我遇到一些代码问题。当我尝试使用“退出”打破我的循环时它不会停止。如果我开始键入quit，它会按预期中断，但第二次循环运行并且我键入退出它没有破坏。有什么问题？

public static void interactionLoop() {
    input = new Scanner(System.in);
    String ssn = null;
    String message = null;
    int accountNr;
    double amount;
    while(true) {
        for(Customers aCustomer : Customers.getCustomerList()) {
            System.out.println(aCustomer.getName() + ", " + aCustomer.getSsn());
        }
        System.out.println("Choose a customer by using SSN.");
        System.out.print(">> ");
        ssn = input.nextLine();
        if(ssn.equals("quit")) {
            break;
        }
        Customers theChosenCustomer = Customers.getCustomerBasedOnSSN(ssn);
        ArrayList<Accounts> accList = theChosenCustomer.getAccountList();

        for(Accounts anAccount : accList) {
            if(anAccount instanceof Savings) {
                System.out.print("(Savings, " + anAccount.getAccountNr() + ")" + "\n");
            }

            if(anAccount instanceof Loans) {
                System.out.print("(Loans, " + anAccount.getAccountNr() + ")" + "\n");
            }

        }

        System.out.print("Enter the account that you want to work with using the account number:\n>> ");
        accountNr = input.nextInt();

        Accounts chosenAccount = theChosenCustomer.getSpecificAccount(accountNr);

        System.out.println("Account balance: "+chosenAccount.getBalance());

        for(Transaction t : chosenAccount.getTransaction()) {
            System.out.println(t.getDateAndTime().getTime() +", " + t.getComment() +": " + t.getAmount());
        }
        System.out.println("\n");

        System.out.print("Please enter the amount of money you wish you withdraw or deposit: ");

        while(input.hasNext()) {
            amount = input.nextDouble();
            input.nextLine();
            if(chosenAccount.isValid(amount)){
                System.out.print("Please enter a comment: ");
                message = input.nextLine();
                Calendar transdatetime = Calendar.getInstance();
                chosenAccount.makeTransaction(new Transaction(transdatetime,message,amount));
                System.out.println("");
                interactionLoop();



            }
        }





    }

Answer 1

accountNr = input.nextInt();

从第2次开始Scanner从Std InpuStream中扫描Integer，但换行符仍然是

ssn = input.nextLine();

因为你的程序没有退出。同样适用于double。更好地使用

BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));

然后使用reader.readLine()并将其解析为所需的数据类型。例如。 Integer.parseInt(reader.readLine())

虽然（真） - 不打破，扫描仪

1 个答案: