net.esper.event.property
Class ArrayFieldPropertyGetter

java.lang.Object
  extended by net.esper.event.property.ArrayFieldPropertyGetter
All Implemented Interfaces:
EventPropertyGetter

public class ArrayFieldPropertyGetter
extends Object
implements EventPropertyGetter

Getter for an array property backed by a field, identified by a given index, using vanilla reflection.


Constructor Summary
ArrayFieldPropertyGetter(Field field, int index)
          Constructor.
 
Method Summary
 Object get(EventBean obj)
          Return the value for the property in the event object specified when the instance was obtained.
 boolean isExistsProperty(EventBean eventBean)
          Returns true if the property exists, or false if the type does not have such a property.
 String toString()
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

ArrayFieldPropertyGetter

public ArrayFieldPropertyGetter(Field field,
                                int index)
Constructor.

Parameters:
field - is the field to use to retrieve a value from the object
index - is tge index within the array to get the property from
Method Detail

get

public final Object get(EventBean obj)
                 throws PropertyAccessException
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
Throws:
PropertyAccessException - to indicate that property access failed

toString

public String toString()
Overrides:
toString in class Object

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