A. it provides centralized request handling for incoming requests.
B. It forces resource authentication to be distributed across web components.
C. It reduces coupling between presentation-tier clients and underlying business services.
D. It can be added and removed unobtrusively， without requiring changes to existing  code.
E. It allows preprocessing and postprocessing on the incoming requests and outgoing  responses.

A. The method invoked by this function must be statie.
B. The function class must implement the Function interface.
C. The expression is NOT a valid EL expression for invoking a function.
D. The function must be declared in a web.xml file using the  element.
E. The function class must have a method with the signature：Void bloof （java.lang.Strings）

A. do GET
B. do Put
C. do Post
D. do Trace
E. do Submit
F. do Process

A. response.set Header （“X-MyHeader”. “34”）：
B. response.addHeader （“X-MyHeader”. “34”）：
C. response. Set Header （new Http Header （“X-MyHeader”. “34”））：
D. response.addHeader（new Http Header （“X-MyHeader”. “34”））：
E. response. addHeader （new Servlet Header （“X-MyHeader”. “34”））：
F. response. setHeader （new Servlet Header （“X-MyHeader”， “34”））：

A. The servlet’s init method returns a non-zero status.
B. The servlet’s init method throws a Servlet Exception
C. The servlet’s init method sets the Servlet Response’s context length to 0
D. The servlet’s init method sets the Servlet Response’s content type to null.
E. The servlet’s init method does NOT return within a time period defined by the servlet container.

A. The do After Body method is called.
B. The doEnd Tag method is NOT called.
C. The type attribute may be specified in the TLD
D. The do Start Tag Method must always return SKIP_BODY.
E. The TLD for this tag must NOT include a  tag.

A. The program runs and prints “ I = 1 ， j = 0”
B. The program runs and prints “ I = 1 ， j = 4”
C. The program runs and prints “ I = 3 ， j = 4”
D. The program runs and prints “ I = 3 ， j = 0”
E. An error at line 4 cause compilation to fail.
F. An error at line 7 cause compilation to fail.

A. An exception is thrown.
B. The code does not compile.
C. “Hello worlds.” Is printed to the terminal.
D. The program exits without printing anything.

A. public double methoda （）：
B. static void methoda（double d1） {}
C. public native double methoda （）：
D. abstract public foid methoda （）：
E. protected void methoda （double d1） {}

A. The code compiles and “s=” is printed.
B. The code compiles and “s=” + s）；
C. The code does not compile because Strings is not initialized.
D. The code does not compile because Strings cannot be referneed.
E. The code comiles， but a NullPointer Exception is thrown when toString is called.