Transaction problems in Stateless EJB

Question

I have problems as follows. my client is a servlet which call method B in stateless ejb, In side of method B, there is a loop from which antoher method C in this same ejb is called repeatedly. I want each call of method C being a separate transaction. I can not make this work. the final result will always be one transaction from for loop. I set the transaction attribute as Requires for method B, and Requires New for method C. Please offer some help.
Thanks.
void ejbMethodB(){
where(mycondition)
ejbMethodC()
I like to make each call of ejbMethodC be a standalone transaction instaed of the running results from the whole loop being a transaction

Answer 1

First of all, thank you so much for your time.
I also doubt the problem is Resin. But "Required" attribut works fine. The following is the coding:
EJB implementation:
//mehtodB
public RequestResult getDailyCreateUpdateInfo(Request request)
throws RemoteException, ProcessException
boolean testFlag = false;
List resultList = null;
ClaimsDAO dao = null;
Map mapRequestData = getRequestData(request);
int num = 0;
InterfacePushProcess push_process = (InterfacePushProcessRemote)(mySessionCtx.getEJBLocalObject());
try {
//Call DAO and get Student, ExchangeVisitor and their dependent information
dao = (ClaimsDAO) getEntityObject(ClaimsDAO.class.getName());
dataPushBO = new ClaimsDataImpl(mapRequestData);
//get the list of categories for DOS or US-VISIT
interdataList = dataPushBO.createCategoryList();
Iterator iterator = interdataList.iterator();
System.out.println("before invokeTransacprocess. ");
//testing
this.invokeTransacProcess();
//process all the categories for DOS or US-VISIT
while(iterator.hasNext())
interconfigData = (InterfaceDataConfig) iterator.next();
processOneCategory(mapRequestData, interconfigData, dao);
} catch (Exception e) {
mySessionCtx.setRollbackOnly();
log.logp(Level.SEVERE, classname, "getDailyCreateUpdateInfo", e.getMessage());
Object[] args = createExceptionArgs();
args[0] = request.getName();
throw new ProcessException(IMessage.ENTITY_POPULATION_FAILED, args, e);
return new RequestResult(request, resultList);
//mehtodC
public void processOneCategory(Map reqmap, InterfaceDataConfig interconfigData, ClaimsDAO dao)
throws ProcessException
List pageList = null;
String fileType = interconfigData.getGroupName(); //student, dep etc
String countKey = interconfigData.getCountKey();
String logKey = interconfigData.getIDKey();
UserTransaction trans = null;
int count = 0;
boolean process = false;
String groupname = interconfigData.getGroupName();
log.logp(Level.INFO, classname, "processOneCategory() ", "group name = " + groupname);
try
Context ct = new InitialContext();
trans = (UserTransaction) ct.lookup("java:comp/UserTransaction");
trans.begin();
String startTime = convert.getTimestamp();
log.logp( Level.INFO, classname, "processOneCategory() ", "processing start time: "+startTime);
pageList = processOnePage(interconfigData, dao);
if (pageList.isEmpty())
log.info("There are no records which need be processed.");
else
do
try
this.displayResult(pageList);
process = pageOutputProcessor(reqmap, interconfigData, pageList);
pageList.clear();
pageList = this.processOnePage(interconfigData, dao);
} catch (Exception ex) {
mySessionCtx.setRollbackOnly();
String msg = "Error while processing one page : " + ex.getMessage();
log.logp(Level.SEVERE, classname, "processOneCategory() ", msg);
throw new ProcessException(msg);
} while (!pageList.isEmpty());
//testing separate transaction
if(groupname.equalsIgnoreCase("STUDENT"))
trans.commit();
else
trans.rollback();
} catch (Exception t) {
mySessionCtx.setRollbackOnly();
String m = "Error when processing results from ClaimsDAO's : " + t.getMessage();
log.logp(Level.SEVERE, classname, "processOneCategory() ", m);
throw new ProcessException(m);
} finally {
I put both methods: getDailyCreateUpdateInfo and processOneCategory in remote interface so I can use your suggested method to reference the EJB instance.
Servlet Client call "getDailyCreateUpdateInfo" method (the transaction attribute is Required) in which call processOneCategory(,,) method (transaction attribute is RequiresNew).
I put some testing code to see if I can achieve the separate transaction in each call of mehtod processOneCategory(,,) , it does not work. If I use Bean Managed Transaction, it works right away. My app. server is Resin 2.1.4.
Again, Thank you.
Mark