The Esper component supports the Esper Library for Event Stream Processing. The camel-esper library is provided by the Camel Extra project which hosts all *GPL related components for Apache Camel.
esper:name[?options]
When consuming from an Esper endpoint you must specify a pattern or eql statement to query the event stream.
For example
from("esper://cheese?pattern=every event=MyEvent(bar=5)"). to("activemq:Foo");
You can append query options to the URI in the following format,
?option=value&option=value&...
Name | Default Value | Description |
---|---|---|
pattern
|
The Esper Pattern expression as a String to filter events | |
eql
|
The Esper EQL expression as a String to filter events |
From Camel 2.12 onwards the esper consumer stores new
and old events in the
org.apacheextras.camel.component.esper.EsperMessage
message as
the input Message on the
Exchange. You can get access
to the esper event beans from java code with:
EventBean newEvent = exchange.getIn(EsperMessage.class).getNewEvent(); EventBean oldEvent = exchange.getIn(EsperMessage.class).getOldEvent();
By default if you get the body of
org.apacheextras.camel.component.esper.EsperMessage
it returns
the new EventBean
as in previous versions.
There is a demo which shows how to work with ActiveMQ, Apache Camel, and Esper in the Camel Extra project