com.tangosol.util.extractor
Class IdentityExtractor

java.lang.Object
  com.tangosol.util.Base
      com.tangosol.util.extractor.AbstractExtractor
          com.tangosol.util.extractor.IdentityExtractor

All Implemented Interfaces:

ExternalizableLite, PortableObject, QueryMapComparator, ValueExtractor, Serializable, Comparator

public class IdentityExtractor
extends AbstractExtractor
implements ExternalizableLite, PortableObject

Trivial ValueExtractor implementation that does not actually extract anything from the passed value, but returns the value itself.

Since:

Coherence 3.2

Author:

jh/gg 2006.03.26

Field Summary

static IdentityExtractor

INSTANCE An instance of the IdentityExtractor.

Constructor Summary

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

Method Summary

boolean	equals(Object o) Compare the IdentityExtractor with another object to determine equality.
Object	extract(Object oTarget) Simply return the passed object.
int	hashCode() Determine a hash value for the IdentityExtractor object according to the general Object.hashCode() contract.
void	readExternal(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.
String	toString() Provide a human-readable description of this IdentityExtractor object.
void	writeExternal(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

Field Detail

INSTANCE

public static final IdentityExtractor INSTANCE

An instance of the IdentityExtractor.

Constructor Detail

IdentityExtractor

public IdentityExtractor()

Default constructor (necessary for the ExternalizableLite interface).

To obtain an instance of an IdentityExtractor use the IdentityExtractor.INSTANCE constant.

Method Detail

extract

public Object extract(Object oTarget)

Simply return the passed object.

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

equals

public boolean equals(Object o)

Compare the IdentityExtractor with another object to determine equality.

Specified by:

equals in interface ValueExtractor

Specified by:

equals in interface Comparator

Parameters:

o - the reference object with which to compare

Returns:

true iff the passed object is an IdentityExtractor

hashCode

public int hashCode()

Determine a hash value for the IdentityExtractor object according to the general Object.hashCode() contract.

Specified by:

hashCode in interface ValueExtractor

Returns:

an integer hash value for this IdentityExtractor object

toString

public String toString()

Provide a human-readable description of this IdentityExtractor object.

Specified by:

toString in interface ValueExtractor

Returns:

a human-readable description of this IdentityExtractor object

readExternal

public void readExternal(DataInput in)
                  throws 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:

IOException - if an I/O exception occurs

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

writeExternal

public void writeExternal(DataOutput out)
                   throws 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:

IOException - if an I/O exception occurs

readExternal

public void readExternal(PofReader in)
                  throws 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:

IOException - if an I/O error occurs

writeExternal

public void writeExternal(PofWriter out)
                   throws 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:

IOException - if an I/O error occurs