单项选择题
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？（）
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？（）
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？（）