A Company.com developer has created a web application that includes a servlet for each use case in the application. These servlets have become rather difficult to maintain because the request processing methods have become very large. There is also common processing code in many servlets because these use cases are very similar. 
Which two design patterns can be used together to refactor and simplify this web application？ （）

单项选择题WhichischaracteristicoftheBusinessDelegatepattern？（）

A. It decreases complexity by removing a layer of proxy classes.
B. It reduces coupling between tiers by hiding implementation details.
C. It decreases performance due to the lack of caching of remote data.
D. It forces business-tier expectations to be dealt with in the presentation-tier.

单项选择题Company.com has decided to use the FUBAR Application Server to host their web application. Unfortunately， the FUBAR Application Server uses the server machine’s file system for its JNDI namespace. Every JNDI lookup performed in the web application is translated into a file 1 0 operation， which results in very poor performance.  Which J2EE pattern can help with this performance issue？（）

A. Transfer Object
B. Service Locator
C. Intercepting Filter
D. Model-View-Controller

单项选择题A Company.com developer is designing a multi-tier web application and discovers a need to hide the details of establishing and maintaining remote communications from the client. In addition， because the business and resource tiers are distributed， the application needs to minimize the inter-tier network traffic related to servicing client requests.  Which design patterns， working together， address these issues？（）

A. Front Controller and Transfer Object
B. Front Controller and Service Locator
C. Business Delegate and Transfer Object
D. Business delegate and Intercepting Filter
E. Model-View-Controller and Intercepting Filter

单项选择题A Company.com developer is designing the presentation tier for a web application that relies on a complex session bean. The session bean is still being developed and the APIs for are NOT finalized. Any changes to the session bean API directly impacts the development of the presentation tier.  Which design pattern provides a means to manage the uncertainty in the API？（）

A. View Helper
B. Front Controller
C. Composite View
D. Intercepting Filter
E. Business Delegate
F. Chain of Responsibility

多项选择题A Company.com developer chooses to avoid using SingleThreadModel but wants to ensure that data is updated in a thread-safe manner.  Which two can support this design goal？（）

A. Store the data in a local variable.
B. Store the data in an instance variable.
C. Store the data in the HttpSession object.
D. Store the data in the ServletContext object.
E. Store the data in the ServletRequest object.