十二、结构型（代理模式）
interface BankAccount {
void deposit(double amount);
void withdraw(double amount);
}
class RealBankAccount implements BankAccount {
private double balance;
public RealBankAccount(double balance) {
this.balance = balance;
}
@Override
public void deposit(double amount) {
balance += amount;
System.out.println("存款成功，当前余额: " + balance);
}
@Override
public void withdraw(double amount) {
if (balance >= amount) {
balance -= amount;
System.out.println("取款成功，当前余额: " + balance);
} else {
System.out.println("余额不足，取款失败");
}
}
}
// 保护代理类
class ProtectionProxy implements BankAccount {
private RealBankAccount realBankAccount;
private String userRole;
public ProtectionProxy(String userRole, double initialBalance) {
this.userRole = userRole;
realBankAccount = new RealBankAccount(initialBalance);
}
@Override
public void deposit(double amount) {
realBankAccount.deposit(amount);
}
@Override
public void withdraw(double amount) {
if ("ADMIN".equals(userRole)) {
realBankAccount.withdraw(amount);
} else {
System.out.println("无权限取款");
}
}
}
// 客户端
public class ProtectionProxyClient {
public static void main(String[] args) {
BankAccount adminAccount = new ProtectionProxy("ADMIN", 1000);
adminAccount.withdraw(500);
BankAccount userAccount = new ProtectionProxy("USER", 1000);
userAccount.withdraw(500);
}
}