Hi Antonio,
On Fri, Jul 25, 2014 at 5:57 PM, Antonio Jesus Navarro < [email protected]> wrote: > Hi all, > > We need in our project the remove callback functionality. Because is not > implemented, we was intended to do an small workaround: > > - The normal creation of parent stream: > > StreamDefinition newStream = > QueryFactory.createStreamDefinition().name(STREAM_NAME); > newStream.attribute("col1", Type.STRING); > newStream.attribute("col2", Type.INT); > sm.defineStream(newStream); > > - Here is the trick. When a callback is added to stream, we generate a > query on the fly because callbacks can be associated to queries: > > String actionQueryId = > sm.addQuery(QueryFactory.createQuery().from(QueryFactory.inputStream(STREAM_NAME))); > > sm.addCallback(actionQueryId, new DummyQueryCallback()); > > - Dummy implementation of QueryCallback: > > public class DummyQueryCallback extends QueryCallback { > @Override > public void receive(long timeStamp, Event[] inEvents, Event[] > removeEvents) { > callbackCalled.set(Boolean.TRUE); > } > } > > - So far so good, all works great. Events are sending correctly to > callback. But when we intend to drop this query, a NullPointerException > appears from QueryManager, line 148: > > streamTableDefinitionMap.remove(query.getOutputStream().getStreamId()); > > We have a few questions: > > - Can you help us with this workaround? > Null pointer exception occurs since the query you have defined does not contain an output ('insert into') clause. You can fix it by doing something like following - i.e. use 'insert into' to define a stream to output the events: String actionQueryId = sm.addQuery(QueryFactory.createQuery().from(QueryFactory.inputStream(STREAM_NAME)).insertInto("outStream")); Refer to this doc [1] which explains the parts of a simple pass-through query for more details. > - It's possible request a "dropCallback" functionality? > You can create a public jira [2] to request new features. They will get added to the next version of the product if they are useful/relevant features. [1[ https://docs.wso2.com/display/CEP310/Pass-through [2] https://wso2.org/jira/browse/CEP Thanks Rajeev > We add an attachment with an small issue test. > > Thanks in advance. > > _______________________________________________ > Architecture mailing list > [email protected] > https://mail.wso2.org/cgi-bin/mailman/listinfo/architecture > > -- Rajeev Sampath Senior Software Engineer WSO2, Inc.; http://www.wso2.com. Mobile: * +94716265766*
_______________________________________________ Architecture mailing list [email protected] https://mail.wso2.org/cgi-bin/mailman/listinfo/architecture
