Thursday, March 01, 2007

JAVA 認證心得 -- SCBCD (2)

Enterprise Java Beans (EJB) Overview

  • A session or entity bean can be redeployed multiple times in the EJB container and each redeployed bean will have a distinct home.
  • Each enterprise bean defines its own set of environment entries. All instances of an enterprise bean within the same home share the same environment entries.
  • Environment entry values of an enterprise bean are not shared with other enterprise beans. Enterprise bean instances are not allowed to modify the bean’s environment at runtime.
  • EJBs are not allowed to make use of package.
  • An EJB container is required to allow synchronized access to multiple users of an entity bean. The bean developer need not worry about the synchronization herself.

Read more!

No comments: