为什么我的break语句脱离整个程序？

Question

The break; statement in my Exception clause stops the entire program if my have improper input to the JOptionPane, it would not execute what I have after the catch block, why is that?

public static void main(String[] args) {
        // TODO Auto-generated method stub
        Customer forrest = new Customer("Forrest Grump", 1,
                "42 New Street, New York, New York");
        Customer random = new Customer("Random Name", 2,
                "44 New Street, New York, New York");
        Customer customer[] = { null, forrest, random };
        int whichOption = 1;
        int id = 0;
        char action = ' ';
        char accSrc = ' ';
        char accDest = ' ';
        double amount = 0;
        BankAccount src = null;
        do {

            try{
            // process JOptionPane input information
            String input = JOptionPane
                    .showInputDialog("Please enter your transaction information: ");
            Scanner s = new Scanner(input);
            id = Integer.parseInt(s.next());
            action = Character.toUpperCase((s.next().charAt(0)));

            if (action == 'T') {
                amount = s.nextDouble();
                accSrc = s.next().charAt(0);
                accDest = s.next().charAt(0);
            } else if (action == 'G' || action == 'I') {
                accSrc = s.next().charAt(0);
            } else {
                // if D,W
                amount = s.nextDouble();
                accSrc = s.next().charAt(0);
            }

            } catch (Exception e){
                System.out.println("Invalid input!");
                break;
            }
            // taking action accordingly (T)ransfer, (D)eposit, (W)ithdraw, (I)nterest
            if (action == 'T') {

                (customer[id].getAccount(accSrc)).transfer(amount,
                        customer[id].getAccount(accDest));
            } else if (action == 'G') {
                System.out.println("The current balance on your " + accSrc
                        + " account is "
                        + customer[id].getAccount(accSrc).getBalance() + "\n");
            } else if (action == 'D') {
                (customer[id].getAccount(accSrc)).deposit(amount);
                //You have successfully depositted $xx.xx
            } else if (action == 'W') {
                (customer[id].getAccount(accSrc)).withdraw(amount);
            } else if (action == 'I') {
                (customer[id].getAccount(accSrc)).computeInterest();
            }
            whichOption = JOptionPane
                    .showConfirmDialog(null , "Do you want to continue?");

            System.out.println("The balance on " + customer[id].getName()
                    + " auto account is " + customer[id].A.balance);
            System.out.println("The balance on " + customer[id].getName()
                    + " savings account is " + customer[id].S.balance);
            System.out.println("The balance on " + customer[id].getName()
                    + " checkings account is " + customer[id].C.balance);
            System.out.println("The balance on " + customer[id].getName()
                    + " loan account is " + customer[id].L.balance + "\n");

        } while (whichOption == 0);

    }
}

Answer 1

because using break you are jumping out of the loop (and that is the end of your program), if you wish to execute after catch block part, simply remove break;

---

See

• document

Answer 2

I suspect you wish to continue , not break . See the difference here:

http://docs.oracle.com/javase/tutorial/java/nutsandbolts/branch.html

continue tells the loops to skip all of the following statements in the loop body and return to the top of the loop body, recheck the condition, and then continue looping normally from there.

break tells the loop to end immediately, ignoring any further instructions in the loop body.

Answer 3

break从封闭循环中逃脱，在您的情况下，这意味着main ...

Answer 4

You're break ing out of the loop and there's nothing left after the loop in your main method. If you want to continue looping, replace the break; with continue; .