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Oracle® Coherence Java API Reference
Release 3.7.0.0

E18683-01


com.tangosol.util.processor
Class ExtractorProcessor

java.lang.Object
  extended by com.tangosol.util.Base
      extended by com.tangosol.util.processor.AbstractProcessor
          extended by com.tangosol.util.processor.ExtractorProcessor

All Implemented Interfaces:
ExternalizableLite, PortableObject, InvocableMap.EntryProcessor, java.io.Serializable

public class ExtractorProcessor
extends AbstractProcessor
implements ExternalizableLite, PortableObject

ExtractorProcessor is an EntryProcessor implementations that extracts a value from an object cached in an InvocableMap. A common usage pattern is:

   cache.invoke(oKey, new ExtractorProcessor(extractor));
 

which is functionally equivalent to the following operation:

   extractor.extract(cache.get(oKey));
 

The major difference is that for clustered caches using the ExtractorProcessor could significantly reduce the amount of network traffic.

Author:
gg 2005.11.30

Field Summary
protected  ValueExtractor m_extractor
          The underlying value extractor.

 

Constructor Summary
ExtractorProcessor()
          Default constructor (necessary for the ExternalizableLite interface).
ExtractorProcessor(java.lang.String sMethod)
          Construct an ExtractorProcessor for a given method name.
ExtractorProcessor(ValueExtractor extractor)
          Construct an ExtractorProcessor based on the specified ValueExtractor.

 

Method Summary
 boolean equals(java.lang.Object o)
          Compare the ExtractorProcessor with another object to determine equality.
 int hashCode()
          Determine a hash value for the ExtractorProcessor object according to the general Object.hashCode() contract.
 java.lang.Object process(InvocableMap.Entry entry)
          Process a Map.Entry object.
 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 ExtractorProcessor.
 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.processor.AbstractProcessor
processAll

 

Field Detail

m_extractor

protected ValueExtractor m_extractor
The underlying value extractor.

Constructor Detail

ExtractorProcessor

public ExtractorProcessor()
Default constructor (necessary for the ExternalizableLite interface).

ExtractorProcessor

public ExtractorProcessor(ValueExtractor extractor)
Construct an ExtractorProcessor based on the specified ValueExtractor.
Parameters:
extractor - a ValueExtractor object; passing null is equivalent to using the IdentityExtractor

ExtractorProcessor

public ExtractorProcessor(java.lang.String sMethod)
Construct an ExtractorProcessor for a given method name.
Parameters:
sMethod - a method name to make a ReflectionExtractor for; this parameter can also be a dot-delimited sequence of method names which would result in an ExtractorProcessor based on the ChainedExtractor that is based on an array of corresponding ReflectionExtractor objects

Method Detail

process

public java.lang.Object process(InvocableMap.Entry entry)
Process a Map.Entry object.
Specified by:
process in interface InvocableMap.EntryProcessor
Parameters:
entry - the Entry to process Note: if this method throws an exception, all modifications to the supplied entry or any other entries retrieved via the BackingMapContext.getBackingMapEntry(java.lang.Object) API will be rolled back leaving all underlying values unchanged.
Returns:
the result of the processing, if any

equals

public boolean equals(java.lang.Object o)
Compare the ExtractorProcessor with another object to determine equality.
Returns:
true iff this ExtractorProcessor and the passed object are equivalent ExtractorProcessor objects

hashCode

public int hashCode()
Determine a hash value for the ExtractorProcessor object according to the general Object.hashCode() contract.
Returns:
an integer hash value for this ExtractorProcessor object

toString

public java.lang.String toString()
Return a human-readable description for this ExtractorProcessor.
Returns:
a String description of the ExtractorProcessor

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

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Oracle® Coherence Java API Reference
Release 3.7.0.0

E18683-01


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