ImageVerifierCode 换一换
格式:DOC , 页数:4 ,大小:40.50KB ,
资源ID:2993863      下载积分:15 文钱
快捷下载
登录下载
邮箱/手机:
温馨提示:
快捷下载时,用户名和密码都是您填写的邮箱或者手机号,方便查询和重复下载(系统自动生成)。 如填写123,账号就是123,密码也是123。
特别说明:
请自助下载,系统不会自动发送文件的哦; 如果您已付费,想二次下载,请登录后访问:我的下载记录
支付方式: 支付宝    微信支付   
验证码:   换一换

加入VIP,省得不是一点点
 

温馨提示:由于个人手机设置不同,如果发现不能下载,请复制以下地址【https://www.wenke99.com/d-2993863.html】到电脑端继续下载(重复下载不扣费)。

已注册用户请登录:
账号:
密码:
验证码:   换一换
  忘记密码?
三方登录: QQ登录   微博登录 

下载须知

1: 本站所有资源如无特殊说明,都需要本地电脑安装OFFICE2007和PDF阅读器。
2: 试题试卷类文档,如果标题没有明确说明有答案则都视为没有答案,请知晓。
3: 文件的所有权益归上传用户所有。
4. 未经权益所有人同意不得将文件中的内容挪作商业或盈利用途。
5. 本站仅提供交流平台,并不能对任何下载内容负责。
6. 下载文件中如有侵权或不适当内容,请与我们联系,我们立即纠正。
7. 本站不保证下载资源的准确性、安全性和完整性, 同时也不承担用户因使用这些下载资源对自己和他人造成任何形式的伤害或损失。

版权提示 | 免责声明

本文(Student_Answers_Chapter_14.doc)为本站会员(11****ws)主动上传,文客久久仅提供信息存储空间,仅对用户上传内容的表现方式做保护处理,对上载内容本身不做任何修改或编辑。 若此文所含内容侵犯了您的版权或隐私,请立即通知文客久久(发送邮件至hr@wenke99.com或直接QQ联系客服),我们立即给予删除!

Student_Answers_Chapter_14.doc

1、Suggested answer for Exercise 14.2A simple-minded implementation of the structure in Figure 14.8 is given below. It is apparent from the code that the abstract supplier interface has not been modified when the new abstract supplier interface was added, and hence that the module is closed. public int

2、erface AbstractSupplierpublic void operation() ;public interface NewAbsSupplier extends AbstractSupplierpublic void newOperation() ;public class ConcreteSupplier implements AbstractSupplierpublic void operation() System.out.println(“ConcreteSupplier:operation() called“) ;public class NewConcSupplier

3、 implements NewAbsSupplierpublic void operation() System.out.println(“NewConcSupplier:operation() called“) ;public void newOperation() System.out.println(“NewConcSupplier:newOperation() called“) ;public class ClientAbstractSupplier supplier ;public Client(AbstractSupplier s) supplier = s ;public voi

4、d doOperation() supplier.operation() ;public class NewClientNewAbsSupplier supplier ;public NewClient(NewAbsSupplier s) supplier = s ;public void doOperation() supplier.operation() ;public void doNewOperation() supplier.newOperation() ;Suggested answer for Exercise 14.5Observer Document/View class O

5、bserver class CView class ConcreteObserver class CMyView Observer.Update() CView.OnDraw() class Subject class CDocument class ConcreteSubject class CMyDoc Subject.Attach() CSubject.AddView() Subject.Detach() CSubject.RemoveView() Subject.Notify() CSubject.UpdateAllViews() Subject.SetState() CSubject

6、.SetStateInfo() Subject.GetState() CSubject.GetStateInfo() This table shows that virtually every feature of Observer can be mapped into a corresponding feature of Document/View. There are two significant differences between the two patterns. Concrete observers hold a reference to their subjects, whe

7、reas in Document/View all references between views and documents are maintained at the abstract level. In practice, this is not very significant, and it can be argued that Document/View supports the association in Observer, as it is simply inherited from the bidirectional association linking the abs

8、tract classes. Another difference is the complexity of the update operation in Document/View. In Observer, the Notify() operation in the subject calls Update() in the observer, which in turn calls GetState(). In Document view, notification calls the OnUpdate() function, whereas it is a different fun

9、ction, OnDraw() which retrieves the document state. Again, however, it can be argued that Document/View does support the interaction defined in Observer, albeit in a not immediately straightforward way. There are therefore strong grounds for regarding Document/View as an instantiation of the Observe

10、r pattern. Suggested answer for Exercise 14.6This question should refer to the document/view architecture in addition to MVC. Figure 14.18 shows an MVC interaction where notification takes place every time the state of the subject (here the model) changes. In the document/view architecture, one opti

11、on would be to have the operation CMyDoc:SetStateInfo() call OnUpdate() every time it are called. This approach has the advantage that client objects which are updating the document dont have to remember to call the notification operation, and the views are guaranteed to be automatically and promptl

12、y made consistent with the document or model state. On the other hand, if a number of consecutive updates are applied to a model, each will cause the corresponding views to be updated independently of the others. It may be sufficient to update the views once, at the end of this sequence of updates,

13、and updating more frequently may be unacceptably inefficient. The alternative would be for objects which update the document to call UpdateAllViews() in the document/view architecture when the update is finished. This allows updates to wait until a sequence of changes has been made, but places an additional responsibility on client objects, thus complicating their implementation and running the risk that updates might, through errors of omission, not be carried out. Because of the role of the controller in MVC, this approach could not be adopted without significant change to the structure.

Copyright © 2018-2021 Wenke99.com All rights reserved

工信部备案号浙ICP备20026746号-2  

公安局备案号:浙公网安备33038302330469号

本站为C2C交文档易平台,即用户上传的文档直接卖给下载用户,本站只是网络服务中间平台,所有原创文档下载所得归上传人所有,若您发现上传作品侵犯了您的权利,请立刻联系网站客服并提供证据,平台将在3个工作日内予以改正。