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.
您可能感兴趣的试卷
你可能感兴趣的试题
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
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
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
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.
A. put（String name. Object value）
B. set（String name. Object value）
C. setAttribute（String name. Object value）
D. putAttribute（String name. Object value）
E. addAttribute（String name. Object value）
B. <filters>
C. <servlet>
D. <filter-list>
Which retrieves the value associated with “foo” from within an HttpServlet？（）
A. String value = getServletConfig（ ）.getParameter（“foo”）；
B. String value = getServletContext（ ）.getAttribute（“foo”）；
C. Object value = getServletContext（ ）.getInitParameter（“foo”）；
D. String value = getServletContext（ ）.getInitParameter（“foo”）
What is the result of a client request of the Source servlet with no query string？（）
A. The output “filterAdded = null” is written to the response stream.
B. The output “filterAdded = addedByFilter” is written to the response stream.
C. An exception is thrown at runtime within the service method of the Source servlet.
D. An exeption is thrown at runtime within the service method of the Destination servlet.
A. response.getWriter（ ）
B. response.getOutputStream（ ）
C. response.getOutputWriter（ ）
D. response.getWriter（ ） .getOutputStream（ ）
E. response.getWriter（Writer.OUTPUT_TEXT（ ）
What is the result？（）
A. <b></b>
B. <b>50</b>
C. <b>${5*10}</b>
D. The JSP fails to execute
最新试题
Which the JSTL code snippet can be used to import content from another web resource？（）
A JSP page， current.jsp， is created to display the current weather report. The weather report is contained in a weather.html page that is rewritten every five minutes. Which line， appearing in current.jsp， ensures that the most recent version of weather.html is included whenever current.jsp is referenced？（）
Within the web application deployment descriptor， which defines a valid JNDI environment entry（）
Which the three are true about servlet filters？（）
Given a JSP error page， which implicit object refers to the uncaught Throwable that resulted in th epage being invoked？（）
Which three can be placed at line 23 to retrieve an existing HttpSession object？（）
When using Form Based Authentication， which pair of fields must be used in the login form？（）
A developer is designing a web application which extensively uses EJBs and JMS. The developer finds that there is a lot of duplicated code to build the JNDI contexts to access the beans and queues. Further， because of the complexity， there are numerous errors in the code. Which J2EE design pattern provides a solution for this problem？（）
What code， inserted at line 21， is called prior to a session being migrated to a different JVM assuming the web application containing MyExample is deployed in a container which supports distributed applications？（）
Which the two are characteristics of the Service Locator pattern？（）