Java Reference
In-Depth Information
There are i ve transitional phases:
BEFORE _ COMPLETION
,
AFTER _ COMPLETION
,
AFTER _ SUCCESS
,
AFTER _ FAILURE
, and the default
IN _ PROGRESS
. In Listing 11‐7, we have not implemented
BEFORE _ COMPLETION
. In Listing 11-8 we implement a class that demonstrates event i ring in
successful and failure scenarios.
LISTING 11‐8:
Provoke success and failure scenarios
package com.devchronicles.observer;
import javax.annotation.Resource;
import javax.ejb.SessionContext;
import javax.ejb.Stateless;
import javax.ejb.TransactionAttribute;
import javax.ejb.TransactionAttributeType;
import javax.enterprise.event.Event;
import javax.inject.Inject;
@Stateless
@TransactionAttribute(TransactionAttributeType.REQUIRED)
public class Children {
@Resource
SessionContext sc;
@Inject
Event<String> message;
int[] children = new int[3];
public void getSixthChild() {
try {
int sixthChild = children[5]; // Throws an IndexOutOfBounds Exception
} catch (Exception e) {
message.fire("Rollback event occurred.");
System.out.println("Exception caught.");
sc.setRollbackOnly();
}
}
public void getThirdChild() {
int thirdChild = children[2]; // Succeeds
message.fire("Successful event");
}
}
The
Children
class simulates a successful transaction in the
getThirdChild
method and an
unsuccessful transaction in the
getSixthChild
method by causing an
IndexOutOfBoundsException
.
You'll examine each method to see how the events are observed. The
getThirdChild
method i res a
String
event, passes it the message
Successful event
, and then i nishes successfully. T he output
from calling this method follows:
