Basic Spring Transactions

Transaction support is available in J2EE as part of the EJB component architecture. For a simple application that is not going to be distributed among many servers the transaction support that is available in Spring is more than efficient.

Spring offers a few options when it comes to transaction management. The most commonly used option is Declarative Transactions because it has the least impact on application code. However, I used the Programmatic Transaction option this was the easiest to implement in the architecture that I was working with. Many who are trying to integrate Spring with legacy code may find this the most feasible option as well. Here are the steps that I used.

First I modified the jboss-spring.xml file to include a bean reference to the JTA Transaction Manager.

jboss-spring.xml

Then in the classes that I wanted to use transactions I added a reference to the bean as a property in the jboss-spring.xml file.

I then needed to add some imports to the actual Java class that would contain the transactional references. The additional functions that I needed to add related to Spring transactions are highlighted in bold.

BookMgmtHandler.java

import org.springframework.transaction.PlatformTransactionManager;
import org.springframework.transaction.TransactionDefinition;
import org.springframework.transaction.TransactionStatus;
import org.springframework.transaction.support.DefaultTransactionDefinition;

public class BookMgmtHandler {
BookDAO BookDAO = null;
BookDataAggregator BookDataAggregator = null;
private PlatformTransactionManager transactionManager = null;

private TransactionDefinition getDefinition() {
DefaultTransactionDefinition def = new    DefaultTransactionDefinition(TransactionDefinition.PROPAGATION_REQUIRED);
return def;}

public Book saveBook(Book book) throws BOOKException {
Book retBook = null;
TransactionStatus status = transactionManager.getTransaction(getDefinition());
// put a block for catching exceptions to rollback the transaction
try {
BookDAO.updateBook(book);
retBook = BookDataAggregator.getBook(book.getBookID());}
catch (BOOKException be){
transactionManager.rollback(status);throw be;}
transactionManager.commit(status);
return retBook;}

public void setTransactionManager(PlatformTransactionManager platformTransactionManager) {this.transactionManager = platformTransactionManager;} 
}

And that's it!