com.tangosol.util.extractor
Class ChainedExtractor

java.lang.Object
  com.tangosol.util.Base
      com.tangosol.util.extractor.AbstractExtractor
          com.tangosol.util.extractor.AbstractCompositeExtractor
              com.tangosol.util.extractor.ChainedExtractor

All Implemented Interfaces:

ExternalizableLite, PortableObject, QueryMapComparator, ValueExtractor, Serializable, Comparator

public class ChainedExtractor
extends AbstractCompositeExtractor

Composite ValueExtractor implementation based on an array of extractors. The extractors in the array are applied sequentially left-to-right, so a result of a previous extractor serves as a target object for a next one.

Author:

gg 2003.09.22

Field Summary

Fields inherited from class com.tangosol.util.extractor.AbstractCompositeExtractor

m_aExtractor

Constructor Summary

ChainedExtractor()
Default constructor (necessary for the ExternalizableLite interface).

ChainedExtractor(String sName)
Construct a ChainedExtractor for a specified method name sequence.

ChainedExtractor(ValueExtractor[] aExtractor)
Construct a ChainedExtractor based on a specified ValueExractor array.

ChainedExtractor(ValueExtractor extractor1, ValueExtractor extractor2)
Construct a ChainedExtractor based on two extractors.

Method Summary

static ValueExtractor[]	createExtractors(String sName) Parse a dot-delimited sequence of method names and instantiate a corresponding array of ReflectionExtractor objects.
Object	extract(Object oTarget) Extract the value from the passed object.

Methods inherited from class com.tangosol.util.extractor.AbstractCompositeExtractor

equals, getExtractors, hashCode, readExternal, readExternal, toString, writeExternal, writeExternal

Methods inherited from class com.tangosol.util.extractor.AbstractExtractor

compare, compareEntries

Constructor Detail

ChainedExtractor

public ChainedExtractor()

Default constructor (necessary for the ExternalizableLite interface).

ChainedExtractor

public ChainedExtractor(ValueExtractor[] aExtractor)

Construct a ChainedExtractor based on a specified ValueExractor array.

Parameters:

aExtractor - the ValueExtractor array

ChainedExtractor

public ChainedExtractor(ValueExtractor extractor1,
                        ValueExtractor extractor2)

Construct a ChainedExtractor based on two extractors.

Parameters:

extractor1 - the ValueExtractor

extractor2 - the ValueExtractor

ChainedExtractor

public ChainedExtractor(String sName)

Construct a ChainedExtractor for a specified method name sequence.

Parameters:

sName - a dot-delimited sequence of method names which results in a ChainedExtractor that is based on an array of corresponding ReflectionExtractor objects

Method Detail

extract

public Object extract(Object oTarget)

Extract the value from the passed object. The underlying extractors are applied sequentially, so a result of a previous extractor serves as a target object for a next one. A value of null prevents any further extractions and is returned immediately. For intrinsic types, the returned value is expected to be a standard wrapper type in the same manner that reflection works; for example, int would be returned as a java.lang.Integer.

Specified by:

extract in interface ValueExtractor

Specified by:

extract in class AbstractExtractor

Parameters:

oTarget - an Object to retrieve the value from

Returns:

the extracted value as an Object; null is an acceptable value

createExtractors

public static ValueExtractor[] createExtractors(String sName)

Parse a dot-delimited sequence of method names and instantiate a corresponding array of ReflectionExtractor objects.

Parameters:

sName - a dot-delimited sequence of method names

Returns:

an array of ReflectionExtractor objects