用javabean 算三个数的加减乘除运算

在Java中，使用JavaBean来计算三个数的加减乘除运算并不直接关联，因为JavaBean主要用于封装数据，而处理数学运算通常会涉及到业务逻辑的实现。然而，我们可以创建一个简单的JavaBean来存储这三数值，并提供对应的getter和setter方法，然后在一个服务类或者业务逻辑类中实现这些运算。

首先，定义一个JavaBean（例如`MathOperationBean.java`）：

public class MathOperationBean {
    private double num1;
    private double num2;
    private double num3;

    // getter and setter methods for the numbers

    public double getNum1() {
        return num1;
    }

    public void setNum1(double num1) {
        this.num1 = num1;
    }

    public double getNum2() {
        return num2;
    }

    public void setNum2(double num2) {
        this.num2 = num2;
    }

    public double getNum3() {
        return num3;
    }

    public void setNum3(double num3) {
        this.num3 = num3;
    }
}

接下来，在一个服务类(`CalculatorService.java`)中，你可以这样计算：

public class CalculatorService {
    private MathOperationBean mathOperation;

    public CalculatorService(MathOperationBean operation) {
        this.mathOperation = operation;
    }

    public double add() {
        return mathOperation.getNum1() + mathOperation.getNum2() + mathOperation.getNum3();
    }

    public double subtract() {
        return mathOperation.getNum1() - mathOperation.getNum2() - mathOperation.getNum3();
    }

    public double multiply() {
        return mathOperation.getNum1() * mathOperation.getNum2() * mathOperation.getNum3();
    }

    public double divide() throws ArithmeticException {
        if (mathOperation.getNum3() != 0) {
            return mathOperation.getNum1() / mathOperation.getNum2() / mathOperation.getNum3();
        } else {
            throw new ArithmeticException("Cannot divide by zero");
        }
    }
}

要使用这个服务，可以这样做：

MathOperationBean bean = new MathOperationBean();
bean.setNum1(5);
bean.setNum2(3);
bean.setNum3(2);

CalculatorService calculator = new CalculatorService(bean);
double sum = calculator.add();
// ...其他运算...