简单工厂模式

/**
 * @Author: subd
 * @Date: 2019/8/28 7:49
 * 简单工程模式
 */
public class SimpleFactoryModel {
    /**
     * 运算类
     */
    public static class Operation {
        private double a = 0;
        private double b = 0;

        public double getA() {
            return a;
        }

        public void setA(double a) {
            this.a = a;
        }

        public double getB() {
            return b;
        }

        public void setB(double b) {
            this.b = b;
        }

        public Double GetResult() {
            double result = 0;
            return result;
        }
    }

    /**
     * 加法运算类继承运算类
     */
    public static class OperationAdd extends Operation {
        @Override
        public Double GetResult() {
            double result = 0;
            result = getA() + getB();
            return result;
        }
    }

    /**
     * 减法运算类继承运算类
     */
    public static class OperationSub extends Operation {
        @Override
        public Double GetResult() {
            double result = 0;
            result = getA() - getB();
            return result;
        }
    }

    /**
     * 乘法运算类继承运算类
     */
    public static class OperationMul extends Operation {
        @Override
        public Double GetResult() {
            double result = 0;
            result = getA() * getB();
            return result;
        }
    }

    /**
     * 除法运算类继承运算类
     */
    public static class OperationDiv extends Operation {
        @Override
        public Double GetResult() {
            double result = 0;
            result = getA() / getB();
            return result;
        }
    }

    public static class OpeationFactory {
        public static Operation CreateOperate(String operate) {
            Operation oper = null;
            switch (operate) {
                case "+":
                    oper = new OperationAdd();
                    break;
                case "-":
                    oper = new OperationSub();
                    break;
                case "*":
                    oper = new OperationMul();
                    break;
                case "/":
                    oper = new OperationDiv();
                    break;
            }
            return oper;
        }
    }

    public static void main(String[] args) {
        Operation operation = OpeationFactory.CreateOperate("+");
        operation.a = 1;
        operation.b = 2;
        double result = operation.GetResult();
        System.out.println(result);
    }
}