import javax.transaction.UserTransaction;
+import org.wamblee.general.ThreadSpecificProxyFactory;
+import org.wamblee.test.persistence.JpaBuilder;
+
/**
- * Simple transaction manager provides a simple mechanism to manage transaction
+ *
+ * <p>
+ * Simple transaction manager provides a simple mechanism to manage transactions
* in test code through the {@link UserTransaction} object.
+ * To construct the transaction manager use:
+ * </p>
+ * <pre>
+ * SimpleTransactionManager manager =
+ * new SimpleTransactionManager(new DefaultUserTransactionFactory());
+ * </pre>
+ *
+ * <p>
+ * Next, add resources to manage using {@link #addResource(TransactionResource)}:
+ * <pre>
+ * manager.addResource(jpaTester.getJpaBuilder());
+ * </pre>
+ * <p>
+ * As you can see from the above, {@link JpaBuilder} is a resource that can be used
+ * so this mechanism can be used with JPA testing.
+ * </p>
+ *
+ * <p>
+ * The next step is to manage transactions using the standard <code>UserTransaction</code>
+ * APIs:
+ * </p>
+ * <pre>
+ * UserTransaction transaction = manager.getTransaction();
+ * transaction.begin();
+ *
+ * ... do work...
+ *
+ * transaction.commit();
+ * </pre>
*
* @author Erik Brakkee
*
public class SimpleTransactionManager {
private UserTransactionFactory factory;
- private ThreadLocal<UserTransaction> current;
+ private ThreadSpecificProxyFactory<UserTransaction> transaction;
private UserTransactionCallback callback;
private List<TransactionResource> resources;
*/
public SimpleTransactionManager(UserTransactionFactory aFactory) {
factory = aFactory;
- current = new ThreadLocal<UserTransaction>();
+ transaction = new ThreadSpecificProxyFactory<UserTransaction>(UserTransaction.class);
callback = new UserTransactionCallback() {
@Override
public void transactionFinished() {
- current.set(null);
+ transaction.set(null);
}
};
resources = new ArrayList<TransactionResource>();
}
/**
- * Gets a transaction associated with the current thread.
+ * Gets the user transaction. This is a contextual reference, meaning that
+ * it will delegate to the appropriate thread-specific user transaction.
+ * It is also safe to store in a JNDI tree and for caching by applications.
*
* @return User transaction.
*/
public UserTransaction getTransaction() {
- UserTransaction transaction = current.get();
- if (transaction == null) {
- transaction = factory.create(callback, resources);
- current.set(transaction);
+ UserTransaction tx = transaction.get();
+ if (tx == null) {
+ tx = factory.create(callback, resources);
+ transaction.set(tx);
}
- return transaction;
+ return transaction.getProxy();
+ }
+
+ /**
+ * Gets the thread-specific transaction object.
+ * @return Transaction object.
+ */
+ UserTransaction getThreadSpecificTransaction() {
+ getTransaction(); // create tx if needed
+ return transaction.get();
}
}