/**
 * @author : [LiuYanQiang]
 * @version : [v1.0]
 * @className : Operation
 * @description : [運算類]
 * @createTime : [2022/5/27 20:04]
 * @updateUser : [LiuYanQiang]
 * @updateTime : [2022/5/27 20:04]
 * @updateRemark : [描述說明本次修改內(nèi)容]
 */
public abstract class Operation {
 
    private double _numberA;
    private double _numberB;
 
    public double get_numberA() {
        return _numberA;
    }
 
    public void set_numberA(double _numberA) {
        this._numberA = _numberA;
    }
 
    public double get_numberB() {
        return _numberB;
    }
 
    public void set_numberB(double _numberB) {
        this._numberB = _numberB;
    }
 
    public abstract double getResult();
}

加法類：

/**
 * @author : [LiuYanQiang]
 * @version : [v1.0]
 * @className : OperationAdd
 * @description : [加法類]
 * @createTime : [2022/5/27 20:13]
 * @updateUser : [LiuYanQiang]
 * @updateTime : [2022/5/27 20:13]
 * @updateRemark : [描述說明本次修改內(nèi)容]
 */
public class OperationAdd extends Operation {
    @Override
    public double getResult() {
        double result = 0;
        result = super.get_numberA() + super.get_numberB();
        return result;
    }
}

減法類：

/**
 * @author : [LiuYanQiang]
 * @version : [v1.0]
 * @className : OperationSub
 * @description : [減法類]
 * @createTime : [2022/5/27 20:13]
 * @updateUser : [LiuYanQiang]
 * @updateTime : [2022/5/27 20:13]
 * @updateRemark : [描述說明本次修改內(nèi)容]
 */
public class OperationSub extends Operation {
    @Override
    public  double getResult() {
        double result = 0;
        result = super.get_numberA() - super.get_numberB();
        return result;
    }
}

乘法類：

/**
 * @author : [LiuYanQiang]
 * @version : [v1.0]
 * @className : OperationMul
 * @description : [乘法類]
 * @createTime : [2022/5/27 20:15]
 * @updateUser : [LiuYanQiang]
 * @updateTime : [2022/5/27 20:15]
 * @updateRemark : [描述說明本次修改內(nèi)容]
 */
public class OperationMul extends Operation {
    @Override
    public double getResult() {
        double result = 0;
        result = super.get_numberA() * super.get_numberB();
        return result;
    }
}

除法類：

/**
 * @author : [LiuYanQiang]
 * @version : [v1.0]
 * @className : OperationDiv
 * @description : [除法類]
 * @createTime : [2022/5/27 20:16]
 * @updateUser : [LiuYanQiang]
 * @updateTime : [2022/5/27 20:16]
 * @updateRemark : [描述說明本次修改內(nèi)容]
 */
public class OperationDiv extends Operation {
    @Override
    public double getResult() {
        double result = 0;
        if (super.get_numberB() == 0) {
            System.out.println("除數(shù)不能為0");
        } else {
            result = super.get_numberA() / super.get_numberB();
        }
        return result;
    }
}

簡單工廠類：

/**
 * @author : [LiuYanQiang]
 * @version : [v1.0]
 * @className : OperationFactory
 * @description : [簡單工廠類]
 * @createTime : [2022/5/27 20:16]
 * @updateUser : [LiuYanQiang]
 * @updateTime : [2022/5/27 20:16]
 * @updateRemark : [描述說明本次修改內(nèi)容]
 */
public class OperationFactory {
    public static Operation createOperation(String operate) {
        Operation operation = null;
        switch (operate) {
            case "+":
                operation = new OperationAdd();
                break;
            case "-":
                operation = new OperationSub();
                break;
            case "*":
                operation = new OperationMul();
                break;
            case "/":
                operation = new OperationDiv();
                break;
        }
        return operation;
    }
}

客戶端主方法類：

/**
 * @author : [LiuYanQiang]
 * @version : [v1.0]
 * @className : Main
 * @description : [客戶端]
 * @createTime : [2022/5/27 20:18]
 * @updateUser : [LiuYanQiang]
 * @updateTime : [2022/5/27 20:18]
 * @updateRemark : [描述說明本次修改內(nèi)容]
 */
public class Main {
    public static void main(String[] args) {
        Operation operation;
        operation=OperationFactory.createOperation("+");
        operation.set_numberA(1);
        operation.set_numberB(2);
        System.out.println(operation.getResult());
    }
}