Java - TreeMap 用户输入

Question

我正在创建一个银行系统项目。

我在将用户输入/扫描仪与树形图合并时遇到问题。

我想创建一个带有帐号的帐户，帐户名以帐号为键。

当帐户被存储后，我将创建一个交易链接列表，该列表仅存储最后 6 笔交易。

有人可以给我一些关于如何根据用户输入将帐户添加到树形图的指导吗？ 命令框？

谢谢。

import java.util.*;
public class Bank {
  TreeMap < Integer, BankAccount > accounts = new TreeMap < Integer, BankAccount > ();



  public int openNewAccount(int accountNumber, String holderName, double openingBalance, String holderAddress, String openDate) {

    }
    //End of Class
}

import java.util.*;
public class BankAccount {
  private int accountNumber;
  private String holderName;
  private String holderAddress;
  private String openDate;
  private double currentBalance;

  private List < Transaction > latestTransactions = new ArrayList < Transaction > ();

  public BankAccount(int accountNum, String holderNam, String holderAdd,
    String openDat) {
    accountNumber = accountNum;
    holderName = holderNam;
    holderAddress = holderAdd;
    openDate = openDat;
  }

  public String getAccountInfo() {
    return "\nAccount number: " + accountNumber + "\nHolder's name: " + holderName + "\nHolder's address: " + holderAddress + "\nOpen Date: " + openDate + "\nCurrent balance: " + currentBalance;
  }

  public int getAccountNum() {
      return accountNumber;
    }
    //End Of Class  

}

import java.util.*;
public class Transaction {
  private List < Transaction > transactions = new ArrayList < Transaction > ();

  public Transaction(int accountNumber, double currentBalance) {

  }

  public void addTransaction(Transaction t) {
    if (transactions.size() + 1 > 6)
      transactions.remove(0); // deletes the list element on the first place

    transactions.add(t);
  }

  public void deposit(double currentBalance, double amount) {

    if (amount <= 0) {
      System.out.println("Amount to be deposited should be positive");
    } else {
      currentBalance = currentBalance + amount;
    }
  }

  public void withdraw(double amount, double currentBalance) {
      if (amount <= 0) {
        System.out.println("Amount to be withdrawn should be positive");
      } else {
        if (currentBalance < amount) {
          System.out.println("Insufficient balance");
        } else {
          currentBalance = currentBalance - amount;
        }
      }
    }
    //End of Class
}

Answer 1

我希望这能帮助您了解该怎么做。

注意:我在里面提供了一些注释以便您能够理解。如果还有不清楚的地方请评论。

银行类别

为您的 Pojo(普通旧 Java 对象)提供 Setter 和 Getter。

public class Bank {

    private int bankId;
    private String bankName;
    private TreeMap<Integer,BankAccount> bankAccounts = new TreeMap<Integer,BankAccount>();

    public Bank(){}

    public Bank(int bankId,String bankName){
        this.bankId = bankId;
        this.bankName = bankName;
    }

    public int getBankId() {
        return bankId;
    }
    public void setBankId(int bankId) {
        this.bankId = bankId;
    }
    public String getBankName() {
        return bankName;
    }
    public void setBankName(String bankName) {
        this.bankName = bankName;
    }
    public TreeMap<Integer, BankAccount> getAccounts() {
        return bankAccounts;
    }
    public void setAccounts(TreeMap<Integer, BankAccount> accounts) {
        this.bankAccounts = accounts;
    }
}

BankAccount 类

public class BankAccount {

    private int accountId;
    private String holderName;
    private String holderAddress;
    private String openDate;
    private double currentBalance;

    private List<Transaction> transactions = new ArrayList<Transaction>();

    //Provide Blank Constructor
    public BankAccount(){}

    //Constructor with an arguments.
    public BankAccount(int accountNum, String holderNam,double currentBalance, String holderAdd,String openDate) {
            this.accountId = accountNum;
            this.holderName = holderNam;
            this.holderAddress = holderAdd;
            this.openDate = openDate;
            this.currentBalance = currentBalance;
    }

    // Always Provide Setter and Getters
    public int getAccountId() {
        return accountId;
    }
    public void setAccountId(int accountId) {
        this.accountId = accountId;
    }
    public String getHolderName() {
        return holderName;
    }
    public void setHolderName(String holderName) {
        this.holderName = holderName;
    }
    public String getHolderAddress() {
        return holderAddress;
    }
    public void setHolderAddress(String holderAddress) {
        this.holderAddress = holderAddress;
    }
    public String getOpenDate() {
        return openDate;
    }
    public void setOpenDate(String openDate) {
        this.openDate = openDate;
    }
    public double getCurrentBalance() {
        return currentBalance;
    }
    public void setCurrentBalance(double currentBalance) {
        this.currentBalance = currentBalance;
    }

    public List<Transaction> getTransactions() {
        return transactions;
    }

    public void setTransactions(List<Transaction> transactions) {
        this.transactions = transactions;
    }

    public String toString(){
        return "\nAccount number: " + accountId + "\nHolder's name: " + holderName + "\nHolder's address: " + holderAddress + "\nOpen Date: " + openDate + "\nCurrent balance: " + currentBalance;
    }

}

交易类

public class Transaction {

    private int transactionId;
    private String transactionType;
    private double transactionAmount;
    private double moneyBeforeTransaction;
    private double moneyAfterTransaction;

    public Transaction(){}

    public Transaction(int transactionId,String transactionType,double transactionAmount, double moneyBeforeTransaction){
        this.transactionId = transactionId;
        this.transactionType = transactionType;
        this.transactionAmount = transactionAmount;
        this.moneyBeforeTransaction = moneyBeforeTransaction;
    }

    public int getTransactionId() {
        return transactionId;
    }

    public void setTransactionId(int transactionId) {
        this.transactionId = transactionId;
    }

    public String getTransactionType() {
        return transactionType;
    }

    public void setTransactionType(String transactionType) {
        this.transactionType = transactionType;
    }

    public double getTransactionAmount() {
        return transactionAmount;
    }

    public void setTransactionAmount(double transactionAmount) {
        this.transactionAmount = transactionAmount;
    }

    public double getMoneyBeforeTransaction() {
        return moneyBeforeTransaction;
    }

    public void setMoneyBeforeTransaction(double moneyBeforeTransaction) {
        this.moneyBeforeTransaction = moneyBeforeTransaction;
    }

    public double getMoneyAfterTransaction() {
        return moneyAfterTransaction;
    }

    public void setMoneyAfterTransaction(double moneyAfterTransaction) {
        this.moneyAfterTransaction = moneyAfterTransaction;
    }

    //Override the toString() method of String ? 
    public String toString(){
        return "Transaction ID : " + this.transactionId +
                " Transaction Type : " + this.transactionType +
                " Transaction Amount : " + this.transactionAmount +
                " Money Before Transaction : " + this.moneyBeforeTransaction + 
                " Money After Transaction : " + this.moneyAfterTransaction;
    }

}

始终将您的交易流程或 POJO 内的任何其他流程分开

看这个。

TransactionProcess 类

public class TransactionProcess {

    //Always Provide another class for process.
    //Pass the bankAccount of the user
    public void deposit(BankAccount bankAccount, double depositAmount) {
        //Get the CurrentBalance
        double currentBalance = bankAccount.getCurrentBalance();

        //First Argument : set the Id of transaction
        //Second Argument : set the Type of Transaction
        //Third Argument : set the TransactionAmount 
        //Fourth Argument : set the Balance Before the transaction (for record purposes)
        Transaction transaction = new Transaction(bankAccount.getTransactions().size(),"Deposit",depositAmount,currentBalance);

        if (depositAmount <= 0) {
            System.out.println("Amount to be deposited should be positive");
        } else {
            //Set the updated or transacted balance of bankAccount.
            bankAccount.setCurrentBalance(currentBalance + depositAmount);
            //then set the MoneyAfterTransaction
            transaction.setMoneyAfterTransaction(bankAccount.getCurrentBalance());
            //after the transaction add it to the list of Transaction of bankAccount
            bankAccount.getTransactions().add(transaction);
        }

    }

    // Explanation same as above
    public void withdraw(BankAccount bankAccount,double withdrawAmount) {
        double currentBalance = bankAccount.getCurrentBalance();
        Transaction transaction = new Transaction(bankAccount.getTransactions().size(),"Withdraw",withdrawAmount,currentBalance);

        if (withdrawAmount <= 0) {
            System.out.println("Amount to be withdrawn should be positive");
        } else {
            if (currentBalance < withdrawAmount) {
                System.out.println("Insufficient balance");
            } else {
                bankAccount.setCurrentBalance(currentBalance - withdrawAmount);
                transaction.setMoneyAfterTransaction(bankAccount.getCurrentBalance());
                bankAccount.getTransactions().add(transaction);
            }
        }

    }

}

BankProcess 类

public class BankProcess {

    // return the  Updated list of BankAccounts
    public TreeMap<Integer,BankAccount> openNewAccount(TreeMap<Integer,BankAccount> bankAccounts,BankAccount bankAccount) {
        //Get the List of existing bank Accounts the add the new BankAccount to it.
        bankAccounts.put(bankAccount.getAccountId(), bankAccount);
        return bankAccounts;
    }

}

最后是主类这将只接受一个银行帐户，创建您自己的流程来接受大量银行帐户。我已经给出了想法。希望你能理解。

Public class MainSample {

    public static void main(String[] args){

        Scanner scan = new Scanner(System.in);

        BankProcess bankProcess = new BankProcess();
        TransactionProcess transactionProcess = new TransactionProcess();

        //Adding new Bank & Bank Account

        // We Already Declare the information about The Back.
        Bank bank = new Bank(1,"GTS");
        BankAccount bankAccount = null;


        //accepting bankAccount informations.

        System.out.print("Account Id: ");
        int accountId = scan.nextInt();

        System.out.print("Holder Name: ");
        String holderName = scan.next();

        System.out.print("Opening Balance: ");
        Double openingBalance = scan.nextDouble();

        System.out.print("Holder Address: ");
        String holderAddress = scan.next();

        System.out.print("Open Date: ");
        String openDate = scan.next();

        //Set the information gathered to BankAccount.
        bankAccount = new BankAccount(accountId,holderName,openingBalance,holderAddress,openDate);

        //Call the Method of BankProcess openNewAccount
        //then set the New|Lastest list of bankaccounts
        bank.setAccounts(bankProcess.openNewAccount(bank.getAccounts(), bankAccount));


        //Here is sample Transaction
        //Deposit.
        System.out.println("Enter Deposit Amount");
        Double depositAmount = scan.nextDouble();

        //This will Process the Transaction of user
        transactionProcess.deposit(bankAccount, depositAmount);

        //Withdraw
        System.out.println("Enter Withdraw Amount");
        Double withdrawAmount = scan.nextDouble();

        transactionProcess.withdraw(bankAccount, withdrawAmount);

        //END


        //this will be Executed After you successfully finished all process 
        //this will provide the list of bankAccount in a certain bank.
        for(Map.Entry<Integer, BankAccount> bankAccounts : bank.getAccounts().entrySet()){
            //Use the toString method of BankAccount, this will Provide all the information of user
            System.out.println(bankAccounts.getValue().toString());
        }

        //This will output the List of the Transactions done by the Current BankAccount(User)
        for(Transaction transaction : bankAccount.getTransactions()){
            System.out.println(transaction.toString());
        }


    }

}

输出是:

Bank Id: 1
Bank Name: SampleBank
Account Id: 1
Holder Name: SampleName
Opening Balance: 10000
Holder Address: SampleAddress
Open Date: SampleDate
Enter Deposit Amount
1000
Enter Withdraw Amount
2000

Account number: 1
Holder's name: SampleName
Holder's address: SampleAddress
Open Date: SampleDate
Current balance: 9000.0
Transaction ID : 0 Transaction Type : Deposit Transaction Amount : 1000.0 Money Before Transaction : 10000.0 Money After Transaction : 11000.0
Transaction ID : 1 Transaction Type : Withdraw Transaction Amount : 2000.0 Money Before Transaction : 11000.0 Money After Transaction : 9000.0