java-工厂方法模式案例

女爷i 2022-06-12 20:37 190阅读 0赞

**题目：**

请使用工厂方法模式实现一个计算器控制台应用程序，包含加、减、乘、除四种运算，要求输入2个数和运算符，输出相应的结果。并画出相应的UML类图？

**类图：**

![Center][]

**代码：**

abstract class Operation {
        private double numberA, numberB;
    
        public double getNumerA() {
            return numberA;
        }
    
        public void setNumberA(double numberA) {
            this.numberA = numberA;
        }
    
        public double getNumerB() {
            return numberB;
        }
    
        public void setNumberB(double numberB) {
            this.numberB = numberB;
        }
    
        public abstract double GetResult();
    
    };
    
    class OperationAdd extends Operation {
        public double GetResult() {
            return getNumerA() + getNumerB();
        }
    };
    
    class OperationSub extends Operation {
        public double GetResult() {
            return getNumerA() - getNumerB();
        }
    };
    
    class OperationMul extends Operation {
        public double GetResult() {
            return getNumerA() * getNumerB();
        }
    };
    
    class OperationDiv extends Operation {
        public double GetResult() {
            return getNumerA() / getNumerB();
        }
    };
    
    class OperationSqrt extends Operation {
        public double GetResult() {
            return Math.sqrt(getNumerA());
        }
    };
    
    interface FactoryOper {
        Operation createOperation();
    };
    
    class AddFactory implements FactoryOper {
        public Operation createOperation() {
            return new OperationAdd();
        }
    };
    
    class SubFactory implements FactoryOper {
        public Operation createOperation() {
            return new OperationSub();
        }
    };
    
    class MulFactory implements FactoryOper {
        public Operation createOperation() {
            return new OperationMul();
        }
    };
    
    class DivFactory implements FactoryOper {
        public Operation createOperation() {
            return new OperationDiv();
        }
    };
    
    class SqrtFactory implements FactoryOper {
        public Operation createOperation() {
            return new OperationSqrt();
        }
    };
    
    public class FactoryMethod {
        public static void main(String[] args){
             FactoryOper operFactory = new MulFactory();
             Operation oper = operFactory.createOperation();
             oper.setNumberA(4);
             oper.setNumberB(2);
             double result = oper.GetResult();
             System.out.println("结果为"+result);
        }
    }

**结果：**

![Center 1][]

[Center]: /images/20220613/d9b860015b494001a6cea0420ac0eac2.png
[Center 1]: /images/20220613/e6a6e88037584d118b2e8cd7cc3a9078.png