代码之家 › 专栏 › 技术社区 › j panton

使用几乎完全重复的代码重构函数,但对其他方法的调用不同

code-duplication refactoring methods intellij-idea java

j panton · 技术社区 · 7 年前

我正在学习Java,正在学习在线课程等,我正在做一个编码练习,发现我的两种方法之间有很多重复,如下所示:

private static void addCustomerTransaction() {
    System.out.println("Enter the branch name:");
    String branchName = scanner.nextLine();

    System.out.println("Enter the customer name:");
    String customerName = scanner.nextLine();

    System.out.println("Enter the transaction");
    while (!scanner.hasNextDouble()) {
        scanner.next();
    }
    double transaction = scanner.nextDouble();

    bank.addCustomerTransaction(branchName,customerName,transaction);

}

private static void addCustomer() {
    System.out.println("Enter the branch name:");
    String branchName = scanner.nextLine();

    System.out.println("Enter the customer name:");
    String customerName = scanner.nextLine();

    System.out.println("Enter the transaction");
    while (!scanner.hasNextDouble()) {
        scanner.next();
    }
    double transaction = scanner.nextDouble();

    bank.addCustomer(branchName,customerName,transaction);
}

我想知道如何重构这些方法以减少重复。我可以做到:

private static void addCustomerTransaction() {
    customerInput();

}

private static void addCustomer() {
    customerInput();
}

private static void customerInput() {
    System.out.println("Enter the branch name:");
    String branchName = scanner.nextLine();

    System.out.println("Enter the customer name:");
    String customerName = scanner.nextLine();

    System.out.println("Enter the transaction");
    while (!scanner.hasNextDouble()) {
        scanner.next();
    }
    double transaction = scanner.nextDouble();

    bank.addCustomerTransaction(branchName,customerName,transaction);
}

但我不知道如何使代码能够更改方法调用(当前 bank.addCustomerTransaction(branchName,customerName,transaction); 在 customerInput 函数调用 .

有人能就下一步提出建议吗?

4 回复 | 直到 7 年前

assylias 7 年前

这里有一个选择。

为最后一个方法创建接口:

@FunctionalInterface public interface CustomerOperation {
  void apply(Bank bank, String branch, String customer, String transaction);
}

private static void customerInput(CustomerOperation operation) {
  //common code here
  operation.apply(bank, branchName, customerName, transaction);
}

你这样称呼它:

private static void addCustomerTransaction() {
  customerInput((bank, branchName, customerName, transaction) ->
      bank.addCustomerTransaction(branchName, customerName, transaction));
}

private static void addCustomer() {
  customerInput((bank, branchName, customerName, transaction) ->
      bank.addCustomer(branchName, customerName, transaction));
}

或者使用方法引用:

private static void addCustomerTransaction() {
  customerInput(Bank::addCustomerTransaction);
}

private static void addCustomer() {
  customerInput(Bank::addCustomer);
}

Yannik 7 年前

public class TransactionInfo {

  private String branchName;
  private String customerName;
  private Double transaction;

  public TransactionInfo(String branchName, String customerName, Double transaction) {
    this.branchName = branchName;
    this.customerName = customerName;
    this.transaction = transaction;
  }

  ...
}

private static TransactionInfo customerInput() {
  System.out.println("Enter the branch name:");
  String branchName = scanner.nextLine();

  System.out.println("Enter the customer name:");
  String customerName = scanner.nextLine();

  System.out.println("Enter the transaction");
  while (!scanner.hasNextDouble()) {
    scanner.next();
  }
  double transaction = scanner.nextDouble();

  return new TransactionInfo(branchName, customerName, transaction);
}

private static void addCustomerTransaction() {
  TransactionInfo transactionInfo = customerInput();
  bank.addCustomerTransaction(transactionInfo.getBranchName(), transactionInfo.getCustomerName(), transactionInfo.getTransaction());
}

private static void addCustomer() {
  TransactionInfo transactionInfo = customerInput();
  bank.addCustomer(transactionInfo.getBranchName(), transactionInfo.getCustomerName(), transactionInfo.getTransaction());
}

如果你能控制 bank ,你可以考虑 addCustomer addCustomerTransaction 方法接受 TransactionInfo 作为参数。

为了那个班。但我希望你能明白。

你的想法是正确的,把公共代码提取到一个方法中。您可以看到,我的解决方案基本上只添加了一个类,供客户输入用作 customerInput

displayName 7 年前

private static double readTransaction() {
    System.out.println("Enter the transaction");
    while (!scanner.hasNextDouble()) {
        scanner.next();
    }
    double transaction = scanner.nextDouble();
    return transaction;
}

private static String readCustomerName() {
    System.out.println("Enter the customer name:");
    String customerName = scanner.nextLine();
    return customerName;
}

private static String readBranch() {
    System.out.println("Enter the branch name:");
    String branchName = scanner.nextLine();
    return branchName;
}

private static void addCustomer() {
    String branchName = readBranch();
    String customerName = readCustomerName();
    double transaction = readTransaction();
    bank.addCustomer(branchName,customerName,transaction);
}

private static void addCustomerTransaction() {
    String branchName = readBranch();
    String customerName = readCustomerName();
    double transaction = readTransaction();
    bank.addCustomerTransaction(branchName,customerName,transaction);
}

而且,你可以 Preserve Whole Object 通过创建包含分支名称、客户名称和事务的类,并执行以下操作:

class Receipt {
    private String customerName;
    private String branchName;
    private double transaction;

    //Getters and setters...

    public void populateReceipt () {
        customerName = readCustomer();
        branchName = readBranch();
        transaction = readTransaction();
    }
}

然后。。。

private void addCustomer (Receipt receipt) {
    //Modify the method to take in a receipt, rather than its 3 components
    bank.addCustomer(receipt);
}

private void addCustomerTransaction (Receipt receipt) {
    //Modify the method to take in a receipt, rather than its 3 components
    bank.addCustomerTransaction(receipt);
}

maha 7 年前

如果要使它们成为addCustomerTransaction或addCustomer,可以使用另一个参数定义函数,如下所示:

private static void addCustomer(boolean transaction) {
System.out.println("Enter the branch name:");
String branchName = scanner.nextLine();

System.out.println("Enter the customer name:");
String customerName = scanner.nextLine();

System.out.println("Enter the transaction");
while (!scanner.hasNextDouble()) {
    scanner.next();
}
double transaction = scanner.nextDouble();

if( transaction ) {
       bank.addCustomerTransaction(branchName,customerName,transaction);
  } else {
      bank.addCustomer(branchName,customerName,transaction);
  }
}