import java.io.IOException; import java.sql.SQLException; /** An ATM that accesses a bank. */ public class ATM { public static final int CHECKING = 1; public static final int SAVINGS = 2; private int state; private int customerNumber; private Customer currentCustomer; private BankAccount currentAccount; private Bank theBank; public static final int START = 1; public static final int PIN = 2; public static final int ACCOUNT = 3; public static final int TRANSACT = 4; /** Constructs an ATM for a given bank. @param aBank the bank to which this ATM connects */ public ATM(Bank aBank) { theBank = aBank; reset(); } /** Resets the ATM to the initial state. */ public void reset() { customerNumber = -1; currentAccount = null; state = START; } /** Sets the current customer number and sets state to PIN. (Precondition: state is START) @param number the customer number. */ public void setCustomerNumber(int number) { assert state == START; customerNumber = number; state = PIN; } /** Finds customer in bank. If found sets state to ACCOUNT, else to START. (Precondition: state is PIN) @param pin the PIN of the current customer */ public void selectCustomer(int pin) throws SQLException { assert state == PIN; currentCustomer = theBank.findCustomer(customerNumber, pin); if (currentCustomer == null) state = START; else state = ACCOUNT; } /** Sets current account to checking or savings. Sets state to TRANSACT. (Precondition: state is ACCOUNT or TRANSACT) @param account one of CHECKING or SAVINGS */ public void selectAccount(int account) { assert state == ACCOUNT || state == TRANSACT; if (account == CHECKING) currentAccount = currentCustomer.getCheckingAccount(); else currentAccount = currentCustomer.getSavingsAccount(); state = TRANSACT; } /** Withdraws amount from current account. (Precondition: state is TRANSACT) @param value the amount to withdraw */ public void withdraw(double value) throws SQLException { assert state == TRANSACT; currentAccount.withdraw(value); } /** Deposits amount to current account. (Precondition: state is TRANSACT) @param value the amount to deposit */ public void deposit(double value) throws SQLException { assert state == TRANSACT; currentAccount.deposit(value); } /** Gets the balance of the current account. (Precondition: state is TRANSACT) @return the balance */ public double getBalance() throws SQLException { assert state == TRANSACT; return currentAccount.getBalance(); } /** Moves back to the previous state. */ public void back() { if (state == TRANSACT) state = ACCOUNT; else if (state == ACCOUNT) state = PIN; else if (state == PIN) state = START; } /** Gets the current state of this ATM. @return the current state */ public int getState() { return state; } }