The Java EE 6 Tutorial, Volume I

Setting Transaction Attributes

Transaction attributes are specified by decorating the enterprise bean class or method with a javax.ejb.TransactionAttribute annotation, and setting it to one of the javax.ejb.TransactionAttributeType constants.

If you decorate the enterprise bean class with @TransactionAttribute, the specified TransactionAttributeType is applied to all the business methods in the class. Decoration a business method with @TransactionAttribute applies the TransactionAttributeType only to that method. If a @TransactionAttributeannotation decorates both the class and the method, the method TransactionAttributeType overrides the class TransactionAttributeType.

The TransactionAttributeType constants encapsulate the transaction attributes described earlier in this section.

The following code snippet demonstrates how to use the @TransactionAttribute annotation:

public class TransactionBean implements Transaction {
    public void firstMethod() {...}

    public void secondMethod() {...}

    public void thirdMethod() {...}

    public void fourthMethod() {...}

In this example, the TransactionBean class’s transaction attribute has been set to NotSupported. firstMethod has been set to RequiresNew, and secondMethod has been set to Required. Because a @TransactionAttribute set on a method overrides the class @TransactionAttribute, calls to firstMethod will create a new transaction, and calls to secondMethod will either run in the current transaction, or start a new transaction. Calls to thirdMethod or fourthMethod do not take place within a transaction.