com.espertech.esper.event.map
Class MapEventBeanPropertyGetter

java.lang.Object
  com.espertech.esper.event.map.MapEventBeanPropertyGetter

All Implemented Interfaces:

EventPropertyGetter, MapEventPropertyGetter

public class MapEventBeanPropertyGetter
extends java.lang.Object
implements MapEventPropertyGetter

A getter for use with Map-based events simply returns the value for the key.

Constructor Summary

MapEventBeanPropertyGetter(java.lang.String propertyName)
Ctor.

Method Summary

java.lang.Object	get(EventBean obj) Return the value for the property in the event object specified when the instance was obtained.
java.lang.Object	getFragment(EventBean obj) Returns EventBean or array of EventBean for a property name or property expression.
java.lang.Object	getMap(java.util.Map<java.lang.String,java.lang.Object> map) Returns a property of an event.
boolean	isExistsProperty(EventBean eventBean) Returns true if the property exists, or false if the type does not have such a property.
boolean	isMapExistsProperty(java.util.Map<java.lang.String,java.lang.Object> map) Exists-function for properties in a map-type event.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

MapEventBeanPropertyGetter

public MapEventBeanPropertyGetter(java.lang.String propertyName)

Ctor.

Parameters:

propertyName - property to get

Method Detail

getMap

public java.lang.Object getMap(java.util.Map<java.lang.String,java.lang.Object> map)
                        throws PropertyAccessException

Description copied from interface: MapEventPropertyGetter

Returns a property of an event.

Specified by:

getMap in interface MapEventPropertyGetter

Parameters:

map - to interrogate

Returns:

property value

Throws:

PropertyAccessException - for property access errors

isMapExistsProperty

public boolean isMapExistsProperty(java.util.Map<java.lang.String,java.lang.Object> map)

Description copied from interface: MapEventPropertyGetter

Exists-function for properties in a map-type event.

Specified by:

isMapExistsProperty in interface MapEventPropertyGetter

Parameters:

map - to interrogate

Returns:

indicator

get

public java.lang.Object get(EventBean obj)

Description copied from interface: EventPropertyGetter

Return the value for the property in the event object specified when the instance was obtained. Useful for fast access to event properties. Throws a PropertyAccessException if the getter instance doesn't match the EventType it was obtained from, and to indicate other property access problems.

Specified by:

get in interface EventPropertyGetter

Parameters:

obj - is the event to get the value of a property from

Returns:

value of property in event

isExistsProperty

public boolean isExistsProperty(EventBean eventBean)

Description copied from interface: EventPropertyGetter

Returns true if the property exists, or false if the type does not have such a property.

Useful for dynamic properties of the syntax "property?" and the dynamic nested/indexed/mapped versions. Dynamic nested properties follow the syntax "property?.nested" which is equivalent to "property?.nested?". If any of the properties in the path of a dynamic nested property return null, the dynamic nested property does not exists and the method returns false.

For non-dynamic properties, this method always returns true since a getter would not be available unless

Specified by:

isExistsProperty in interface EventPropertyGetter

Parameters:

eventBean - is the event to check if the dynamic property exists

Returns:

indictor whether the property exists, always true for non-dynamic (default) properties

getFragment

public java.lang.Object getFragment(EventBean obj)

Description copied from interface: EventPropertyGetter

Returns EventBean or array of EventBean 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 EventBean 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.

Specified by:

getFragment in interface EventPropertyGetter

Parameters:

obj - is the event to get the fragment value of a property

Returns:

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