Message-driven bean:Attributes

[vinod balaji]

I have a doubt in Message-driven beans transaction attribute.
In HFEJB PGNO 500, it is given that MDB can use only TWO attributes:Requires and NotSupported.
Iam not understanding what it means. Can anyone brief this.

Thank You

[Christophe Verré]

Only the NotSupported and Required transaction attributes may be used for message-driven beans. The use of the other transaction attributes is not meaningful for message-driven beans because there can be no pre-existing transaction context (RequiresNew, Supports) and no client to handle exceptions (Mandatory, Never).

Note that it is Required, not Requires

[vinod balaji]

Thank you for Your nice note.Now Iam clear

[Steven Gao Song]

Hi, Satou,

What do you mean by "there can be no pre-existing transaction context"?

The Required transaction attribute can promise a pre-existing tran-context?

[Christophe Verré]

What do you mean by "there can be no pre-existing transaction context"?

If there were one, it would be suspended, which is not possible for message driven beans as there's no client.