摘要：
类图：1 public interface IFactory {2 public Operation createOperation();3 }1 public class AddOperationFactory implements IFactory {2 3 @Override4... 阅读全文
摘要：
类图：代码： 1 public class Operation { 2 3 protected double numberA = 0; 4 protected double numberB = 0; 5 6 7 public double getNumb... 阅读全文