net.sf.ehcache.search.attribute
Interface AttributeExtractor

All Superinterfaces:

Serializable

All Known Implementing Classes:

JavaBeanAttributeExtractor, KeyObjectAttributeExtractor, ReflectionAttributeExtractor, ValueObjectAttributeExtractor

public interface AttributeExtractor
extends Serializable

Used to extract a search attribute value for a given cache element.

Instances must be Serializable in order to ensure identical extractors are used in distributed caches

Author:

teck

Method Summary

Object

attributeFor(Element element, String attributeName) Extract the attribute value.

Method Detail

attributeFor

Object attributeFor(Element element,
                    String attributeName)
                    throws AttributeExtractorException

Extract the attribute value. The instance returned from this method must be one of:

• java.lang.Boolean
• java.lang.Byte
• java.lang.Character
• java.lang.Double
• java.lang.Float
• java.lang.Integer
• java.lang.Long
• java.lang.Short
• java.lang.String
• java.util.Date
• java.sql.Date
• java.lang.Enum

NOTE: null is a legal return here as well indicating that this attribute will not be available for the given element

Parameters:

element - the cache element to inspect

attributeName - the name of the requested attribute

Returns:

the attribute value

Throws:

AttributeExtractorException - if the attribute cannot be found or extracted