net.sf.ehcache.search.attribute
Class ReflectionAttributeExtractor

java.lang.Object
  net.sf.ehcache.search.attribute.ReflectionAttributeExtractor

All Implemented Interfaces:

Serializable, AttributeExtractor

public class ReflectionAttributeExtractor
extends Object
implements AttributeExtractor

Built-in search attribute extractor driven by method/value dotted expression chains.

The expression chain must start with one of either "key", "value", or "element". From the starting object a chain of either method calls or field names follows. Method calls and field names can be freely mixed in the chain. Some examples:

1. "key.getName()" -- call getName() on the key object
2. "value.person.getAge()" -- get the "person" field of the value object and call getAge() on it
3. "element.toString()" -- call toString() on the element

The method and field name portions of the expression are case sensitive

Author:

teck

See Also:

Serialized Form

Constructor Summary

ReflectionAttributeExtractor(String expression)
Create a new ReflectionAttributeExtractor

Method Summary

Object

attributeFor(Element e, String attributeName) Evaluate the expression for the given element

Methods inherited from class java.lang.Object

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

Constructor Detail

ReflectionAttributeExtractor

public ReflectionAttributeExtractor(String expression)
                             throws InvalidConfigurationException

Create a new ReflectionAttributeExtractor

Parameters:

expression -

Throws:

InvalidConfigurationException

Method Detail

attributeFor

public Object attributeFor(Element e,
                           String attributeName)
                    throws AttributeExtractorException

Evaluate the expression for the given element

Specified by:

attributeFor in interface AttributeExtractor

Parameters:

e - the cache element to inspect

attributeName - the name of the requested attribute

Returns:

the attribute value

Throws:

AttributeExtractorException - if there is an error in evaluating the expression