A、 A web application may override the web container’s implementation classes

B、 A web application running in a J2EE product may override classes in the javax.* namespace

C、 A web application class loader may NOT override any classes in the java.* and javax.*  namespace

D、 Resources in the WAR class directory or in any of the JAR files within the library directory may  be accessed using the J2SE semantics of getResource

E、 Resources in the WAR class directory or in any of the JAR files within the library directory  cannot be accessed using the J2SE semantics of getResource