JTA Transaction Management

Divided

CMT container management transactions (recommended)

@ Transactionmanagement (transactionmanagementtype. Container) (Class-level annotation)

Container indicates that the CMT container manages transactions, and bean indicates BMT Management

@ Transactionattribute (transactionattributetype. required) (method-level annotation)

 

	Non-transactional context Client	Transaction context Client
Required	New transactions	Classified as a superior transaction
Required_new	New transactions	Pending a superior transaction, new transaction
Supports	Normal	Classified as machine transaction
Mandatory	Exception	Classified as a superior transaction
Not_supported	Normal	Pending upper-level transactions
Never	Normal	Exception

The essence of supports is to support any transaction environment

Not_supported this attribute is only used in non-transactional automatic validation mode that supports MDB of the JMS provider

@ Resource // inject the EJB Context

Private sessioncontext context;

 

Context. setrollbackonly (); // an exception occurs during rollback.

BMT bean manages transactions, manages transactions by hard coding, and controls transaction boundaries.

(When usertransaction is used to manage a transaction, the upper-level transaction will be suspended)

@ Resource

Private usertransaction; // inject usertransaction

Usertransaction. Begin (); // start the transaction Boundary

Usertransaction. Commit (); // submit

Usertransaction. rollback (); // transaction boundary ends

Note: usertransaction can also be obtained through JNDI lookup.

And from sessioncontext context (EJB context), context. getusertransaction ()

Implementation exception class

@ Applicationexception (rollback = true)

// Rollback is false by default. If it is true, exception will be rolled back before being returned to the client.

Class XXX extends exception {}

All checked exceptions (except java. RMI. RemoteException) are expected to be application exception.
Java. RMI. RemoteException and non-checked exception are regarded as system exception

System exception is not directly transmitted to the client, but is saved as ejbexception by the container.