com.espertech.esper.event.bean

Class NestedPropertyGetter

java.lang.Object

com.espertech.esper.event.bean.BaseNativePropertyGetter

com.espertech.esper.event.bean.NestedPropertyGetter

All Implemented Interfaces:

EventPropertyGetter, BeanEventPropertyGetter

public class NestedPropertyGetter
extends BaseNativePropertyGetter
implements BeanEventPropertyGetter

Getter for one or more levels deep nested properties.

Constructor Summary

Constructors

Constructor and Description
NestedPropertyGetter(List<EventPropertyGetter> getterChain, EventAdapterService eventAdapterService, Class finalPropertyType, Class finalGenericType) Ctor.

Method Summary

Modifier and Type	Method and Description
Object	get(EventBean eventBean) Return the value for the property in the event object specified when the instance was obtained.
Object	getBeanProp(Object value) Returns the property as an object.
boolean	isBeanExistsProperty(Object value) Returns true if the dynamic property exists.
boolean	isExistsProperty(EventBean eventBean) Returns true if the property exists, or false if the type does not have such a property.

Methods inherited from class com.espertech.esper.event.bean.BaseNativePropertyGetter

getFragment, getFragmentDynamic

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.espertech.esper.client.EventPropertyGetter

getFragment

Constructor Detail

NestedPropertyGetter

public NestedPropertyGetter(List<EventPropertyGetter> getterChain,
                            EventAdapterService eventAdapterService,
                            Class finalPropertyType,
                            Class finalGenericType)

Ctor.

Parameters:

getterChain - is the chain of getters to retrieve each nested property

eventAdapterService - is the cache and factory for event bean types and event wrappers

finalPropertyType - type of the entry returned

finalGenericType - generic type parameter of the entry returned, if any

Method Detail

getBeanProp

public Object getBeanProp(Object value)
                   throws PropertyAccessException

Description copied from interface: BeanEventPropertyGetter

Returns the property as an object.

Specified by:

getBeanProp in interface BeanEventPropertyGetter

Parameters:

value - to evaluate

Returns:

property of object

Throws:

PropertyAccessException - if access failed

isBeanExistsProperty

public boolean isBeanExistsProperty(Object value)

Description copied from interface: BeanEventPropertyGetter

Returns true if the dynamic property exists.

Specified by:

isBeanExistsProperty in interface BeanEventPropertyGetter

Parameters:

value - to evaluate

Returns:

indicator if property exists

get

public Object get(EventBean eventBean)
           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:

eventBean - 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

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