java创建银行账户类SavingAccount，用静态成员变量存储年利率，用私有成员变量存储存款余额。提供计算年利息的方法和计算月利息（年利息/12）的方法。在主函数中建立SavingAccount的对象saver，从控制台输入存款额度和年利率，输出年利息和月利息。

以下是Java代码实现：

import java.util.Scanner;

public class SavingAccount {
    private double balance; // 存款余额
    private static double annualInterestRate; // 年利率

    public SavingAccount(double balance) {
        this.balance = balance;
    }

    // 设置年利率
    public static void setAnnualInterestRate(double rate) {
        annualInterestRate = rate;
    }

    // 计算年利息
    public double calculateAnnualInterest() {
        return balance * annualInterestRate;
    }

    // 计算月利息
    public double calculateMonthlyInterest() {
        return calculateAnnualInterest() / 12;
    }

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.print("请输入存款额度：");
        double balance = scanner.nextDouble();
        System.out.print("请输入年利率：");
        double annualInterestRate = scanner.nextDouble();

        SavingAccount saver = new SavingAccount(balance);
        SavingAccount.setAnnualInterestRate(annualInterestRate);

        double annualInterest = saver.calculateAnnualInterest();
        double monthlyInterest = saver.calculateMonthlyInterest();

        System.out.println("年利息为：" + annualInterest);
        System.out.println("月利息为：" + monthlyInterest);
    }
}

运行结果：

请输入存款额度：10000
请输入年利率：0.05
年利息为：500.0
月利息为：41.666666666666664