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EJB MDB doubt

Prasad Shindikar
Ranch Hand

Joined: Feb 18, 2007
Posts: 114
The container serializes calls to each message-driven bean instance. Most containers will
support many instances of a message-driven bean executing concurrently; however, each
instance sees only a serialized sequence of method calls. Therefore, a message-driven bean
DOES NOT have to be coded as reentrant.

what does it mean when said
MDBs should not be coded as reentrant
Umakanth Godavarthy
Ranch Hand

Joined: Nov 10, 2005
Posts: 37
"reentrant" means a multi-threaded environment where a method can be executed concurrently by different threads. This is not applicable to MDBs as everytime a message listener method is executed (or a timer callback) a new instance is picked up by the container from the pool.

Hope this answers.
 
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subject: EJB MDB doubt