class Person {
    public void speak() {
        System.out.println("person");
    }
}

class Chinese extends Person {
    @Override
    public void speak() {
        System.out.println("Chinese");
    }

    public void chinaNo1() {
        System.out.println("chinaNo1");
    }
}

class English extends Person {
    @Override
    public void speak() {
        System.out.println("English");
    }
}

public class SimpleFactory {
    public static void main(String args[]) {
        Person person1 = new Chinese();
        Person person2 = new English();
        person1.speak();
        person2.speak();
        //person1.chinaNo1(); 多态下父类引用变量无法直接调用子类特有的方法
        Chinese chinese = (Chinese) person1;
        chinese.chinaNo1();
    }

}

import java.util.Scanner;

class Operation {
    private double numberOne = 0;
    private double numberTwo = 0;

    public double getNumberOne() {
        return numberOne;
    }

    public void setNumberOne(double numberOne) {
        this.numberOne = numberOne;
    }

    public double getNumberTwo() {
        return numberTwo;
    }

    public void setNumberTwo(double numberTwo) {
        this.numberTwo = numberTwo;
    }

    public double getResult() throws Exception {
        double result = 0;
        return result;
    }
}

class OperationAdd extends Operation {
    @Override
    public double getResult() {
        return getNumberOne() + getNumberTwo();
    }
}

class OperationSub extends Operation {
    @Override
    public double getResult() {
        return getNumberOne() - getNumberTwo();
    }
}

class OperationMul extends Operation {
    @Override
    public double getResult() {
        return getNumberOne() * getNumberTwo();
    }
}

class OperationDiv extends Operation {
    @Override
    public double getResult() throws Exception {
        if (getNumberTwo() == 0) {
            throw new Exception("除数不能为0");
        }
        return getNumberOne() / getNumberTwo();
    }
}

class OperationFactory {
    public static Operation createOperation(char operation) throws Exception {
        switch (operation) {
            case ‘+‘: {
                return new OperationAdd();
            }
            case ‘-‘: {
                return new OperationSub();
            }
            case ‘*‘: {
                return new OperationMul();
            }
            case ‘/‘: {
                return new OperationDiv();
            }
            default: {
                throw new Exception("不支持的计算类型");
            }
        }
    }
}

public class SimpleFactory {
    public static void main(String args[]) {
        Scanner sc = new Scanner(System.in);
        double number1 = sc.nextDouble();
        System.out.println(number1);
        char op = sc.next().charAt(0);
        System.out.println(op);
        double number2 = sc.nextDouble();
        System.out.println(number2);
        Operation operation = null;
        try {
            operation = OperationFactory.createOperation(op);
        } catch (Exception e) {
            e.printStackTrace();
        }
        operation.setNumberOne(number1);
        operation.setNumberTwo(number2);
        try {
            System.out.println(operation.getResult());
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

}