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Oracle® Coherence Java API Reference
Release 3.7.0.0

E18683-01


com.tangosol.util.extractor
Class ConditionalExtractor

java.lang.Object
  extended by com.tangosol.util.Base
      extended by com.tangosol.util.BitHelper
          extended by com.tangosol.util.ExternalizableHelper
              extended by com.tangosol.util.extractor.AbstractExtractor
                  extended by com.tangosol.util.extractor.ConditionalExtractor

All Implemented Interfaces:
ExternalizableLite, PortableObject, QueryMapComparator, IndexAwareExtractor, ValueExtractor, java.io.Serializable, java.util.Comparator

public class ConditionalExtractor
extends AbstractExtractor
implements IndexAwareExtractor, ExternalizableLite, PortableObject

An IndexAwareExtractor implementation that is only used to create a ConditionalIndex.

Note: the underlying ValueExtractor is used for value extraction during index creation and is the extractor that is associated with the created ConditionalIndex in the given index map. Using the ConditionalExtractor to extract values in not supported.

Since:
Coherence 3.6
Author:
tb 2010.02.08

Field Summary
protected  ValueExtractor m_extractor
          The underlying extractor.
protected  boolean m_fForwardIndex
          Specifies whether or not this extractor will create a ConditionalIndex that supports a forward index.
protected  Filter m_filter
          The filter used by this extractor.

 

Fields inherited from class com.tangosol.util.extractor.AbstractExtractor
KEY, m_nTarget, VALUE

 

Constructor Summary
ConditionalExtractor()
          Construct the ConditionalExtractor.
ConditionalExtractor(Filter filter, ValueExtractor extractor, boolean fForwardIndex)
          Construct the ConditionalExtractor.

 

Method Summary
 MapIndex createIndex(boolean fOrdered, java.util.Comparator comparator, java.util.Map mapIndex, BackingMapContext ctx)
          Create an index and associate it with the corresponding extractor.
 MapIndex destroyIndex(java.util.Map mapIndex)
          Destroy an existing index and remove it from the given map of indexes.
 boolean equals(java.lang.Object o)
          Compare the ValueExtractor with another object to determine equality.
 java.lang.Object extract(java.lang.Object oTarget)
          Using a ConditionalExtractor to extract values in not supported.
 int hashCode()
          Determine a hash value for the ValueExtractor object according to the general Object.hashCode() contract.
 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.
 java.lang.String toString()
          Return a human-readable description for this ConditionalExtractor.
 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, extractFromEntry, extractOriginalFromEntry

 

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

 

Field Detail

m_filter

protected Filter m_filter
The filter used by this extractor.

m_extractor

protected ValueExtractor m_extractor
The underlying extractor.

m_fForwardIndex

protected boolean m_fForwardIndex
Specifies whether or not this extractor will create a ConditionalIndex that supports a forward index.

Constructor Detail

ConditionalExtractor

public ConditionalExtractor()
Construct the ConditionalExtractor.

ConditionalExtractor

public ConditionalExtractor(Filter filter,
                            ValueExtractor extractor,
                            boolean fForwardIndex)
Construct the ConditionalExtractor.
Parameters:
filter - the filter used by this extractor to create a ConditionalIndex; must not be null.
extractor - the extractor used by this extractor to create a ConditionalIndex; Note that the created index will be associated with this extractor in the given index map; must not be null
fForwardIndex - specifies whether or not this extractor will create a ConditionalIndex that supports a forward map

Method Detail

createIndex

public MapIndex createIndex(boolean fOrdered,
                            java.util.Comparator comparator,
                            java.util.Map mapIndex,
                            BackingMapContext ctx)
Create an index and associate it with the corresponding extractor. Important note: it is a responsibility of this method's implementations to place the necessary <ValueExtractor, MapIndex> entry into the given map of indexes.
Specified by:
createIndex in interface IndexAwareExtractor
Parameters:
fOrdered - true iff the contents of the indexed information should be ordered; false otherwise
comparator - the Comparator object which imposes an ordering of entries in the index contents; or null if the entries' values natural ordering should be used
mapIndex - Map<ValueExtractor, MapIndex> to be updated with the created index
ctx - The context the index is associate with.
Returns:
the created index; null if the index has not been created

destroyIndex

public MapIndex destroyIndex(java.util.Map mapIndex)
Destroy an existing index and remove it from the given map of indexes.
Specified by:
destroyIndex in interface IndexAwareExtractor
Parameters:
mapIndex - map<ValueExtractor, MapIndex> to be updated by removing the index being destroyed
Returns:
the destroyed index; null if the index does not exist

extract

public java.lang.Object extract(java.lang.Object oTarget)
Using a ConditionalExtractor to extract values in not supported.
Specified by:
extract in interface ValueExtractor
Overrides:
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
Throws:
java.lang.UnsupportedOperationException - always

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

equals

public boolean equals(java.lang.Object o)
Compare the ValueExtractor with another object to determine equality. Two ValueExtractor objects, ve1 and ve2 are considered equal iff ve1.extract(o) equals ve2.extract(o) for all values of o.
Specified by:
equals in interface ValueExtractor
Specified by:
equals in interface java.util.Comparator
Parameters:
o - the reference object with which to compare
Returns:
true iff this ValueExtractor and the passed object are equivalent ValueExtractors
See Also:
Object.equals(java.lang.Object), Object.hashCode()

hashCode

public int hashCode()
Determine a hash value for the ValueExtractor object according to the general Object.hashCode() contract.
Specified by:
hashCode in interface ValueExtractor
Returns:
an integer hash value for this ValueExtractor object

toString

public java.lang.String toString()
Return a human-readable description for this ConditionalExtractor.
Specified by:
toString in interface ValueExtractor
Returns:
a String description of the ConditionalExtractor

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Oracle® Coherence Java API Reference
Release 3.7.0.0

E18683-01


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