Declaring Event as a Map

Question

Hi experts,
I have encountered some problem in declaring an event type as a map. For some reason, when I use the sample provided by oracle:
<wlevs:event-type type-name="AnotherEvent">
*<wlevs:property>* <-- this requires a name but since I am using a map, this should not be a problem
<entry key="name" value="java.lang.String"/>
<entry key="age" value="java.lang.Integer"/>
<entry key="address" value="java.lang.String"/>
</wlevs:property>
I encountered an exception nested exception is org.xml.sax.SAXParseException cvc-complex-type.4: Attribute 'name' must appear on element 'wlevs:property'. Since I followed the example I am expecting that it should run without problem but the example itself gives me an exception. Did I miss something or do I need to update some library?
The next question is, in CEP example, it only gives you how to declare the map in the cep context.xml, but it did not give any example in how to access the map within the java code. Is there any of you who tried to access the map in java code and passed it in the channel? Can you post a sample code? Help is greatly appreciated.
Regards,
Russel

Answer 1

through Anand Srinivasan     
I am using HelloWorld to illustrate how your requirement can be met ---
1) First in the assembly file, define the event-type as a Tuple
<wlevs:event-type-repository>
<wlevs:event-type type-name="HelloWorldEvent">
<wlevs:properties>
<wlevs:property name="message" type="char" length="200"/>
</wlevs:properties>
</wlevs:event-type>
</wlevs:event-type-repository>
2) In the HelloWorldAdapter -
@Service
public void setEventTypeRepository(EventTypeRepository etr) {
etr_ = etr;
private void generateHelloMessage() {
String message = this.message + dateFormat.format(new Date());
// HelloWorldEvent event = new HelloWorldEvent();
EventType type = etr_.getEventType("HelloWorldEvent");
EventProperty messageProp = type.getProperty("message");
Object event = type.createEvent();
messageProp.setValue(event, message);
eventSender.sendInsertEvent(event);
This illustrates how you can create an event (Tuple) and send the Tuple downstream. The same approach can be followed in the HelloWorldBean (the "B" part of your app - to send to the "C" part of your app)
3) HelloWorldBean - the "B" part of your app
First of all here is how you can read the data in the tuple -
@Service
public void setEventTypeRepository(EventTypeRepository etr) {
etr_ = etr;
public void onInsertEvent(Object event) {
EventType eventType = etr_.getEventType(event);     
String prop = (String)eventType.getPropertyValue(event, "message");
System.out.println("Tuple Message: " + prop);
Now, since you want to send further downstream to a "C", you will need to do the following -
public class HelloWorldBean implements StreamSource, StreamSink
Once you decide to implement "StreamSource", you will need -
public void setEventSender(StreamSender sender) {
streamSender_ = sender;
Then, use a similar approach as in the adapter to instantiate a new event, populate its properties and then call "streamSender_.sendInsertEvent"