您好我是用Java创建银行应用程序。
我的问题是我不知道如何删除已创建的帐户。
当我创建一个新帐户时，它会获得一个新号码，但如果有3个帐户，我想知道如何删除帐户，我想删除帐号2，当我想创建一个帐号时它将获得ID号2的新帐户。（有1号和3号）。
当我想创建另一个帐户时，我想将其ID更改为4.
提前致谢。 ：）
import java.util.Scanner;
public class BankApp {
public static void main(String[] args) {
Scanner s = new Scanner(System.in);
Bank myBank = new Bank();
int user_choice = 2;
do {
//display menu to user
//ask user for his choice and validate it (make sure it is between 1 and 6)
System.out.println();
System.out.println("1) Open a new bank account");
System.out.println("2) Deposit to a bank account");
System.out.println("3) Withdraw to bank account");
System.out.println("4) Print short account information");
System.out.println("5) Print the detailed account information including last transactions");
System.out.println("6) Quit");
System.out.println();
System.out.print("Enter choice [1-6]: ");
user_choice = s.nextInt();
switch (user_choice) {
case 1: System.out.println("Enter a customer name");
String cn = s.next();
System.out.println("Enter a opening balance");
double d = s.nextDouble();
System.out.println("Account was created and it has the following number: " + myBank.openNewAccount(cn, d));
break;
case 2: System.out.println("Enter a account number");
int an = s.nextInt();
System.out.println("Enter a deposit amount");
double da = s.nextDouble();
myBank.depositTo(an, da);
break;
case 3: System.out.println("Enter a account number");
int acn = s.nextInt();
System.out.println("Enter a withdraw amount");
double wa = s.nextDouble();
myBank.withdrawFrom(acn, wa);
break;
case 4: System.out.println("Enter a account number");
int anum = s.nextInt();
myBank.printAccountInfo(anum);
break;
case 5: System.out.println("Enter a account number");
anum = s.nextInt();
myBank.printTransactionInfo(anum);
break;
default: System.out.println("Invalid option. Please try again.");
}
}
while (user_choice != '6');
}
static class Bank {
private BankAccount[] accounts; // all the bank accounts at this bank
private int numOfAccounts; // the number of bank accounts at this bank
//Constructor: A new Bank object initially doesn’t contain any accounts.
public Bank() {
accounts = new BankAccount[100];
numOfAccounts = 0;
}
// Creates a new bank account using the customer name and the opening balance given as parameters
// and returns the account number of this new account. It also adds this account into the account list
// of the Bank calling object.
public int openNewAccount(String customerName, double openingBalance) {
BankAccount b = new BankAccount(customerName, openingBalance);
accounts[numOfAccounts] = b;
numOfAccounts++;
return b.getAccountNum();
}
// Withdraws the given amount from the account whose account number is given. If the account is
// not available at the bank, it should print a message.
public void withdrawFrom(int accountNum, double amount) {
for (int i =0; i<numOfAccounts; i++) {
if (accountNum == accounts[i].getAccountNum() ) {
accounts[i].withdraw(amount);
System.out.println("Amount withdrawn successfully");
return;
}
}
System.out.println("Account number not found.");
}
// Deposits the given amount to the account whose account number is given. If the account is not
// available at the bank, it should print a message.
public void depositTo(int accountNum, double amount) {
for (int i =0; i<numOfAccounts; i++) {
if (accountNum == accounts[i].getAccountNum() ) {
accounts[i].deposit(amount);
System.out.println("Amount deposited successfully");
return;
}
}
System.out.println("Account number not found.");
}
// Prints the account number, the customer name and the balance of the bank account whose
// account number is given. If the account is not available at the bank, it should print a message.
public void printAccountInfo(int accountNum) {
for (int i =0; i<numOfAccounts; i++) {
if (accountNum == accounts[i].getAccountNum() ) {
System.out.println(accounts[i].getAccountInfo());
return;
}
}
System.out.println("Account number not found.");
}
public void printTransactionInfo(int accountNum) {
for (int i =0; i<numOfAccounts; i++) {
if (accountNum == accounts[i].getAccountNum() ) {
System.out.println(accounts[i].getAccountInfo());
System.out.println("Last transaction: " + accounts[i].getTransactionInfo(accounts[i].getNumberOfTransactions()-1));
return;
}
}
System.out.println("Account number not found.");
}
// Prints the account number, the customer number and the balance of the bank account whose
// account number is given, together with last n transactions on that account. If the account is not
// available at the bank, it should print a message.
public void printAccountInfo(int accountNum, int n) {
for (int i =0; i<numOfAccounts; i++) {
if (accountNum == accounts[i].getAccountNum() ) {
System.out.println(accounts[i].getAccountInfo());
System.out.println(accounts[i].getTransactionInfo(n));
return;
}
}
System.out.println("Account number not found.");
}
}
static class BankAccount{
private int accountNum;
private String customerName;
private double balance;
private double[] transactions;
private String[] transactionsSummary;
private int numOfTransactions;
private static int noOfAccounts=0;
public String getAccountInfo(){
return "Account number: " + accountNum + "\nCustomer Name: " + customerName + "\nBalance:" + balance +"\n";
}
public String getTransactionInfo(int n)
{
String transaction = transactionsSummary[n];
if (transaction == null) {
return "No transaction exists with that number.";
}
else {
return transaction;
}
}
public BankAccount(String abc, double xyz){
customerName = abc;
balance = xyz;
noOfAccounts ++;
accountNum = noOfAccounts;
transactions = new double[100];
transactionsSummary = new String[100];
transactions[0] = balance;
transactionsSummary[0] = "A balance of : $" + Double.toString(balance) + " was deposited.";
numOfTransactions = 1;
}
public int getAccountNum(){
return accountNum;
}
public int getNumberOfTransactions() {
return numOfTransactions;
}
public void deposit(double amount){
if (amount<=0) {
System.out.println("Amount to be deposited should be positive");
} else {
balance = balance + amount;
transactions[numOfTransactions] = amount;
transactionsSummary[numOfTransactions] = "$" + Double.toString(amount) + " was deposited.";
numOfTransactions++;
}
}
public void withdraw(double amount)
{
if (amount<=0){
System.out.println("Amount to be withdrawn should be positive");
}
else
{
if (balance < amount) {
System.out.println("Insufficient balance");
} else {
balance = balance - amount;
transactions[numOfTransactions] = amount;
transactionsSummary[numOfTransactions] = "$" + Double.toString(amount) + " was withdrawn.";
numOfTransactions++;
}
}
}
}//end of class
}
答案 0 :(得分：1)
原则上重新使用帐号是错误的，但如果你坚持这样做：
您可能希望将帐户标记为有效或无效。创建帐户时，请将其标记为活动。删除帐户时，请将其标记为非活动状态。
当程序决定“新”帐户的帐号时，首先获取所有非活动帐户的有序列表，然后选择第一个帐户。如果没有任何非活动帐户，则使用递增的numOfAccounts变量。
答案 1 :(得分：0)
也许你应该考虑重新思考这个的逻辑。 但是，解决方案可能是将银行帐户标记为删除，添加字段，例如：
class BankAccount{
...
private boolean isMarkedForDeletion = false;
...
}
并向其添加getters and setters。
现在你会：
1）当删除帐户时，请将该字段切换为true。
public int closeAccount(int id) {
boolean isAccountFound = false;
int i = 0;
while(i < numOfAccounts && isAccountFound == false)
{
// if() // Add here the condition to find the account to delete.
// { accounts[i].isMarkedForDeletion = true; }
}
现在，不再对此帐户执行任何存款或其他操作。
2）当创建新帐户时，循环浏览每个现有帐户并验证帐户是否标记为删除 - 可能使用 while 循环。 如果要找到一个帐户＆＃34;标记为删除= true＆＃34;那么你会重新声明当前迭代的元素是一个与旧ID相同的新帐户。
public int openNewAccount(String customerName, double openingBalance) {
BankAccount b = new BankAccount(customerName, openingBalance);
boolean isAccountFound = false;
int i = 0;
while(isAccountFound == false && i < accounts.length)
{
// if() add conditions for this account to replace the old one.
// hint: use the isMarkedForDeletion field!
// Finally add the new value assignment ( accounts[i] = ... )
// return the account number.
}
// This will happen in the case there were no matches.
accounts[numOfAccounts] = b;
numOfAccounts++;
return b.getAccountNum();
}
答案 2 :(得分：0)
我会使用一个事实，即可能有最大数量的帐户（100），因此数组大小固定。
public int openNewAccount(String customerName, double openingBalance) {
for (int i = 0; i < 100; i++) {
if (accounts[i] == null) { //Empty slot
BankAccount b = new BankAccount(customerName, openingBalance);
b.accountNum = i + 1;
break;
}
}
return b.getAccountNum();
}
并且删除意味着将该插槽设置为空
public void deleteAccount(int accountNo) {
accounts[accountNo - 1] = null;
}
这两种方法都可能使用某种错误处理方法，具体取决于所需的反馈。您还需要从BankAccount构造函数中删除不必要的内容。