com.espertech.esper.client

Interface EventBean

All Known Subinterfaces:

AvroBackedBean, EventBeanSPI, MappedEventBean, ObjectArrayBackedEventBean

All Known Implementing Classes:

BeanEventBean, MapEventBean, NaturalEventBean, ObjectArrayEventBean, RevisionEventBeanDeclared, RevisionEventBeanMerge, VariantEventBean, WrapperEventBean, XMLEventBean

public interface EventBean

Interface for event representation. All events have an EventType. Events also usually have one or more event properties. This interface allows the querying of event type, event property values and the underlying event object.

Method Summary

Modifier and Type	Method and Description
Object	get(String propertyExpression) Returns the value of an event property for the given property name or property expression.
EventType	getEventType() Return the EventType instance that describes the set of properties available for this event.
Object	getFragment(String propertyExpression) Returns event beans or array of event bean for a property name or property expression.
Object	getUnderlying() Get the underlying data object to this event wrapper.

Method Detail

getEventType

EventType getEventType()

Return the EventType instance that describes the set of properties available for this event.

Returns:

event type

get

Object get(String propertyExpression)
    throws PropertyAccessException

Returns the value of an event property for the given property name or property expression.

Returns null if the property value is null. Throws an exception if the expression is not valid against the event type.

The method takes a property name or property expression as a parameter. Property expressions may include indexed properties via the syntax "name[index]", mapped properties via the syntax "name('key')", nested properties via the syntax "outer.inner" or combinations thereof.

Parameters:

propertyExpression - - name or expression of the property whose value is to be retrieved

Returns:

the value of a property with the specified name.

Throws:

PropertyAccessException - - if there is no property of the specified name, or the property cannot be accessed

getUnderlying

Object getUnderlying()

Get the underlying data object to this event wrapper.

Returns:

underlying data object, usually either a Map or a Java bean instance.

getFragment

Object getFragment(String propertyExpression)
            throws PropertyAccessException

Returns event beans or array of event bean for a property name or property expression.

For use with properties whose value is itself an event or whose value can be represented as an event by the underlying event representation.

The EventType of the event bean instance(s) returned by this method can be determined by EventType.getFragmentType(String). Use EventPropertyDescriptor to obtain a list of properties that return fragments from an event type.

Returns null if the property value is null or the property value cannot be represented as a fragment by the underlying representation.

The method takes a property name or property expression as a parameter. Property expressions may include indexed properties via the syntax "name[index]", mapped properties via the syntax "name('key')", nested properties via the syntax "outer.inner" or combinations thereof.

Parameters:

propertyExpression - - name or expression of the property whose value is to be presented as an EventBean or array of EventBean

Returns:

the value of a property as an EventBean or array of EventBean

Throws:

PropertyAccessException - - if there is no property of the specified name, or the property cannot be accessed