This section discusses the Esper integration with OSWorkflow to process business event data and react with user-defined patterns.
To enable Esper functionality inside an OSWorkflow definition, we must create a way to emit events from OSWorkflow into the Esper engine.
OSWorkflow can provide this extension via a custom FunctionProvider. This FunctionProvider will emit events into the engine. The code for the class is as follows:
package packtpub.osw.cep;
import java.util.Map;
import net.esper.client.*;
import com.opensymphony.module.propertyset.PropertySet;
import com.opensymphony.util.BeanUtils;
import com.opensymphony.workflow.FunctionProvider;
import com.opensymphony.workflow.WorkflowException;
/**
* Function provider that sends an event to the esper engine.
*/
public class PushEventFunctionProvider implements FunctionProvider
{
public void execute(Map transientVars, Map args, PropertySet ps)
throws WorkflowException
{
// the event POJO...