You can embed Java code snippets directly into the BPEL process using the Java BPEL exec extension bpelx:exec. The benefits of this approach are speed and transactionality. It is recommended that you incorporate only small segments of code. BPEL is about separation of business logic from implementation. If you remove a lot of Java code in your process, you lose that separation. Java embedding is recommended for short utility-like operations, rather than business code. Place the business logic elsewhere and call it from BPEL.

The server executes any snippet of Java code contained within a bpelx:exec activity, within its Java Transaction API (JTA) transaction context.The BPEL tag bpelx:exec converts Java exceptions into BPEL faults and then adds them into the BPEL process.The Java snippet can propagate its JTA transaction to session and entity beans that it calls.

For example, a SessionBeanSample.bpel file uses the bpelx:exec tag shown in the following code to embed the invokeSessionBean Java bean:

 <bpelx:exec name="invokeSessionBean" language="java" version="1.5">
    <![CDATA[
        try {
            Object homeObj = lookup("ejb/session/CreditRating");
            Class cls = Class.forName(
                "com.otn.samples.sessionbean.CreditRatingServiceHome");
            CreditRatingServiceHome ratingHome = (CreditRatingServiceHome)
                        PortableRemoteObject.narrow(homeObj,cls);
            if (ratingHome == null) {
                addAuditTrailEntry("Failed to lookup 'ejb.session.CreditRating'"
                                   + ". Ensure that the bean has been"
                                   + " successfully deployed");
                return;
            }
            CreditRatingService ratingService = ratingHome.create();
 
            // Retrieve ssn from scope
            Element ssn =
                (Element)getVariableData("input","payload","/ssn");
 
            int rating = ratingService.getRating( ssn.getNodeValue() );
            addAuditTrailEntry("Rating is: " + rating);
 
            setVariableData("output", "payload",
                "/tns:rating", new Integer(rating));
        } catch (NamingException ne) {
            addAuditTrailEntry(ne);
        } catch (ClassNotFoundException cnfe) {
            addAuditTrailEntry(cnfe);
        } catch (CreateException ce) {
            addAuditTrailEntry(ce);
        } catch (RemoteException re) {
            addAuditTrailEntry(re);
        }
    ]]>
    </bpelx:exec>