工厂模式--简单工厂模式

简单说说简单工厂模式：

需求：设计个计算器，两个数字之间的加减乘除基本运算。

首先是Operation运算抽象类：

package com.SimpleFactory;

/**
 * 简单工厂模式
 * @Description: 运算抽象类
 * @Date 2018/7/25
 */
public abstract class Operation {
    public double number1;
    public double number2;

    public double getNumber1() {
        return number1;
    }

    public void setNumber1(double number1) {
        this.number1 = number1;
    }

    public double getNumber2() {
        return number2;
    }

    public void setNumber2(double bumber2) {
        this.number2 = bumber2;
    }

    public abstract double getResult() throws Exception;
}

继承Operation的加法类：OperationAdd加法运算类

package com.SimpleFactory;

/**
 * 简单工厂模式
 * @Description: 加法
 * @Date 2018/7/25
 */
public class OperationAdd extends Operation {
    @Override
    public double getResult() {
        return number1 + number2;
    }
}

继承Operation的减法类：OperationSub减法运算类

package com.SimpleFactory;

/**
 * 简单工厂模式
 * @Description: 减法
 * @Date 2018/7/25
 */
public class OperationSub extends Operation {
    @Override
    public double getResult() {
        return number1 - number2;
    }
}

继承Operation的乘法类：OperationMul乘法运算类

package com.SimpleFactory;

/**
 * 简单工厂模式
 * @Description: 乘法
 * @Date 2018/7/25
 */
public class OperationMul extends Operation {
    @Override
    public double getResult() {
        return number1 * number2;
    }
}

继承Operation的除法类：OperationDiv除法运算类

package com.SimpleFactory;

/**
 * 简单工厂模式
 * @Description: 除法
 * @Date 2018/7/25
 */

public class OperationDiv extends Operation {
  @Override
    public double getResult() throws Exception {
      if (number2 == 0){
          throw new Exception("除数不能为0");
      }
      return number1/number2;
  }
}

生成Operation的工厂类：OperationFactory

package com.SimpleFactory;

/**
 * 简单工厂模式
 * @Description: 生成Operation的工厂类
 * @Date 2018/7/25
 */
public class OperationFactory {
    public static Operation createOperation(char operation) {
        Operation oper = null;
        switch (operation) {
            case '+':
                oper =new OperationAdd();
                break;
            case '-':
                oper =new OperationSub();
                break;
            case '*':
                oper =new OperationMul();
                break;
            case '/':
                oper =new OperationDiv();
                break;
            default:
                break;
        }
        return oper;
    }
}

测试类：

package com.SimpleFactory;

/**
 * 简单工厂模式
 * @Description: 测试简单工厂模式
 * @Date 2018/7/25
 */
public class Test {
    public static void main(String[] args) {
        Operation oper;
        oper = OperationFactory.createOperation('/');
        oper.number1 = 1;
        oper.number2 = 2;
        try {
            System.out.println(oper.getResult());
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

}