建立一個簡單的 Java 帳戶管理系統,包含基本的增刪改查功能,適合初學者練習物件導向設計、集合框架應用與檔案持久化。
public class Account {
private String id;
private String name;
private double balance;
private String password;
// 建構子、Getter/Setter、toString 等
}
import java.util.*;
public class AccountManager {
private Map accounts = new HashMap<>();
public void addAccount(Account acc) { ... }
public void deleteAccount(String id) { ... }
public Account findAccount(String id) { ... }
public void deposit(String id, double amount) { ... }
public void withdraw(String id, double amount) { ... }
public void saveToFile(String filename) { ... }
public void loadFromFile(String filename) { ... }
}
BigDecimal 避免浮點數精度問題serialVersionUID