Oracle® Coherence Java API Reference
v3.5

E14977-01

com.tangosol.util.extractor
Class ReflectionExtractor

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

public class ReflectionExtractor
extends AbstractExtractor
implements ValueExtractor, ExternalizableLite, PortableObject

Reflection-based ValueExtractor implementation.

Author:
cp/gg 2002.11.01, ew 2007.02.01
See Also:
ChainedExtractor

Field Summary
protected  java.lang.Object[] m_aoParam
          The parameter array.
protected  java.lang.String m_sMethod
          The name of the method to invoke.
 
Fields inherited from class com.tangosol.util.extractor.AbstractExtractor
KEY, m_nTarget, VALUE
 
Constructor Summary
ReflectionExtractor()
          Default constructor (necessary for the ExternalizableLite interface).
ReflectionExtractor(java.lang.String sMethod)
          Construct a ReflectionExtractor based on a method name.
ReflectionExtractor(java.lang.String sMethod, java.lang.Object[] aoParam)
          Construct a ReflectionExtractor based on a method name and optional parameters.
ReflectionExtractor(java.lang.String sMethod, java.lang.Object[] aoParam, int nTarget)
          Construct a ReflectionExtractor based on a method name, optional parameters and the entry extraction target.
 
Method Summary
 boolean equals(java.lang.Object o)
          Compare the ReflectionExtractor with another object to determine equality.
 java.lang.Object extract(java.lang.Object oTarget)
          Extract the value from the passed object. The returned value may be null. 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.
 java.lang.String getMethodName()
          Determine the name of the method that this extractor is configured to invoke.
 java.lang.Object[] getParameters()
          Return the array of arguments used to invoke the method.
 int hashCode()
          Determine a hash value for the ReflectionExtractor 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()
          Provide a human-readable description of this ReflectionExtractor 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, 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
 

Field Detail

m_sMethod

protected java.lang.String m_sMethod
The name of the method to invoke.


m_aoParam

protected java.lang.Object[] m_aoParam
The parameter array.

Constructor Detail

ReflectionExtractor

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


ReflectionExtractor

public ReflectionExtractor(java.lang.String sMethod)
Construct a ReflectionExtractor based on a method name.

Parameters:
sMethod - the name of the method to invoke via reflection

ReflectionExtractor

public ReflectionExtractor(java.lang.String sMethod,
                           java.lang.Object[] aoParam)
Construct a ReflectionExtractor based on a method name and optional parameters.

Parameters:
sMethod - the name of the method to invoke via reflection
aoParam - the array of arguments to be used in the method invocation; may be null
Since:
Coherence 3.3

ReflectionExtractor

public ReflectionExtractor(java.lang.String sMethod,
                           java.lang.Object[] aoParam,
                           int nTarget)
Construct a ReflectionExtractor based on a method name, optional parameters and the entry extraction target.

Parameters:
sMethod - the name of the method to invoke via reflection
aoParam - the array of arguments to be used in the method invocation; may be null
nTarget - one of the AbstractExtractor.VALUE or AbstractExtractor.KEY values
Since:
Coherence 3.5
Method Detail

extract

public java.lang.Object extract(java.lang.Object oTarget)
Extract the value from the passed object. The returned value may be null. 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
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

equals

public boolean equals(java.lang.Object o)
Compare the ReflectionExtractor with another object to determine equality. Two ReflectionExtractor objects, re1 and re2 are considered equal iff re1.extract(o) equals re2.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 ReflectionExtractor and the passed object are equivalent ReflectionExtractors

hashCode

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

Specified by:
hashCode in interface ValueExtractor
Returns:
an integer hash value for this ReflectionExtractor object

toString

public java.lang.String toString()
Provide a human-readable description of this ReflectionExtractor object.

Specified by:
toString in interface ValueExtractor
Returns:
a human-readable description of this ReflectionExtractor object

getMethodName

public java.lang.String getMethodName()
Determine the name of the method that this extractor is configured to invoke.

Returns:
the name of the method to invoke using reflection

getParameters

public java.lang.Object[] getParameters()
Return the array of arguments used to invoke the method.

Returns:
the array of arguments used to invoke the method

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

Oracle® Coherence Java API Reference
v3.5

E14977-01

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