简化Java代码：面向对象编程原则示例

原创左手的ㄟ右手 2024-09-16 11:09 73阅读 0赞

在Java中，面向对象编程（Object-Oriented Programming, OOP）有五个核心原则：封装、继承、多态和接口。

以下是一些简化代码的OOP原则示例：

1. 封装（Encapsulation）：
```java
public class BankAccount {
    private double balance;

public BankAccount(double initialBalance) {
        this.balance = initialBalance;
    }

// Getter and Setter for balance
    public double getBalance() {
        return balance;
    }

public void setBalance(double newBalance) {
        if (newBalance >= 0) {
            this.balance = newBalance;
        } else {
            System.out.println("Invalid balance. Can't be negative.");
        }
    }
}
```
2. 继承（Inheritance）：
```java
public class SavingsAccount extends BankAccount {
    public SavingsAccount(double initialBalance) {
        super(initialBalance); // calling superclass constructor
    }

// Override methods to add functionality specific to SavingsAccount
    @Override
    public void setInterestRate(double interestRate) {
        this.balance += (balance * interestRate) / 100; // calculating interest
    }
}
```
3. 多态（Polymorphism）：
```java
public interface Transactionable {
    void performTransaction();
}

// Implementations of Transactional interfaces
class SavingsAccountImpl extends SavingsAccount implements Transactionable {
    @Override
    public void performTransaction() {
        System.out.println("Performing transaction in SavingsAccount.");
        setInterestRate(0.05); // Adding 5% interest to simulate a transaction
    }
}

public class Main {
    public static void main(String[] args) {
        SavingsAccount account = new SavingsAccountImpl(1000);
        
        account.performTransaction(); // Simulating a transaction by calling performTransaction()

System.out.println("Balance after transaction: " + account.getBalance());
    }
}
```
以上示例展示了如何使用Java的OOP原则简化代码。