com.tangosol.util.extractor
Class EntryExtractor

java.lang.Object
  com.tangosol.util.Base
      com.tangosol.util.BitHelper
          com.tangosol.util.ExternalizableHelper
              com.tangosol.util.extractor.AbstractExtractor
                  com.tangosol.util.extractor.EntryExtractor

All Implemented Interfaces:

ExternalizableLite, PortableObject, QueryMapComparator, ValueExtractor, java.io.Serializable, java.util.Comparator

public abstract class EntryExtractor
extends AbstractExtractor
implements PortableObject, ExternalizableLite

The EntryExtractor is a base abstract class for special purpose custom ValueExtractor implementations. It allows them to extract a desired value using all available information on the corresponding Map.Entry object and is intended to be used in advanced custom scenarios, when application code needs to look at both key and value at the same time or can make some very specific assumptions regarding to the implementation details of the underlying Entry object. As of Coherence 3.5, the same behavior can be achieved by subclasses of the AbstractExtractor by overriding the AbstractExtractor.extractFromEntry().

Since:

Coherence 3.4

Author:

gg 2008.04.14

Field Summary

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

KEY, m_nTarget, VALUE

Constructor Summary

EntryExtractor()
Default constructor (for backward compatibilty).

EntryExtractor(int nTarget)
Construct an EntryExtractor based on the entry extraction target.

Method Summary

void	readExternal(java.io.DataInput in) Restore the contents of this object by loading the object's state from the passed DataInput object.
void	readExternal(PofReader in) Restore the contents of a user type instance by reading its state using the specified PofReader object.
void	writeExternal(java.io.DataOutput out) Save the contents of this object by storing the object's state into the passed DataOutput object.
void	writeExternal(PofWriter out) Save the contents of a POF user type instance by writing its state using the specified PofWriter object.

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

compare, compareEntries, extract, extractFromEntry

Methods inherited from class com.tangosol.util.BitHelper

countBits, countBits, countBits, indexOfLSB, indexOfLSB, indexOfLSB, indexOfMSB, indexOfMSB, indexOfMSB, rotateLeft, rotateLeft, rotateLeft, rotateRight, rotateRight, rotateRight, toBitString, toBitString, toBitString

Methods inherited from interface com.tangosol.util.ValueExtractor

equals, hashCode, toString

Methods inherited from interface java.util.Comparator

equals

Constructor Detail

EntryExtractor

public EntryExtractor()

Default constructor (for backward compatibilty).

EntryExtractor

public EntryExtractor(int nTarget)

Construct an EntryExtractor based on the entry extraction target.

Parameters:

nTarget - one of the AbstractExtractor.VALUE or AbstractExtractor.KEY values

Since:

Coherence 3.5

Method Detail

readExternal

public void readExternal(java.io.DataInput in)
                  throws java.io.IOException

Restore the contents of this object by loading the object's state from the passed DataInput object.

Specified by:

readExternal in interface ExternalizableLite

Parameters:

in - the DataInput stream to read data from in order to restore the state of this object

Throws:

java.io.IOException - if an I/O exception occurs

java.io.NotActiveException - if the object is not in its initial state, and therefore cannot be deserialized into

writeExternal

public void writeExternal(java.io.DataOutput out)
                   throws java.io.IOException

Save the contents of this object by storing the object's state into the passed DataOutput object.

Specified by:

writeExternal in interface ExternalizableLite

Parameters:

out - the DataOutput stream to write the state of this object to

Throws:

java.io.IOException - if an I/O exception occurs

readExternal

public void readExternal(PofReader in)
                  throws java.io.IOException

Restore the contents of a user type instance by reading its state using the specified PofReader object.

Specified by:

readExternal in interface PortableObject

Parameters:

in - the PofReader from which to read the object's state

Throws:

java.io.IOException - if an I/O error occurs

writeExternal

public void writeExternal(PofWriter out)
                   throws java.io.IOException

Save the contents of a POF user type instance by writing its state using the specified PofWriter object.

Specified by:

writeExternal in interface PortableObject

Parameters:

out - the PofWriter to which to write the object's state

Throws:

java.io.IOException - if an I/O error occurs