ReflectionExtractor Class Reference

#include <coherence/util/extractor/ReflectionExtractor.hpp>

Inherits AbstractExtractor.

List of all members.


Detailed Description

Reflection-based ValueExtractor implementation.

Author:
djl 2008.03.06
See also:
ChainedExtractor

Public Types

typedef spec::Handle Handle
 ReflectionExtractor Handle definition.
typedef spec::View View
 ReflectionExtractor View definition.
typedef spec::Holder Holder
 ReflectionExtractor Holder definition.

Public Member Functions

virtual Object::Holder extract (Object::Holder ohTarget) const
 Extract the value from the passed object.

The returned value may be NULL.

Parameters:
ohTarget an Object to retrieve the value from
Returns:
the extracted value; NULL is an acceptable value
Exceptions:
ClassCastException if this ValueExtractor is incompatible with the passed object to extract a value from and the implementation requires the passed object to be of a certain type
Exception if this ValueExtractor encounters an exception in the course of extracting the value
IllegalArgumentException if this ValueExtractor cannot handle the passed object for any other reason; an implementor should include a descriptive message

virtual void readExternal (PofReader::Handle hIn)
 
virtual void writeExternal (PofWriter::Handle hOut) const
 
virtual bool equals (Object::View v) const
 Compare the ValueExtractor with another object to determine equality.

Two ValueExtractor objects, ve1 and ve2 are considered equal iff ve1->extract(v) equals ve2->extract(v) for all values of v.

Parameters:
v the reference object with which to compare
Returns:
true iff this ValueExtractor and the passed object are equivalent ValueExtractors

virtual size32_t hashCode () const
 Return a hash code value for the Object.

This method is supported for the benefit of hash-based containers.

The general contract of hashCode is:

  • Whenever it is invoked on the same Object more than once during an execution of an application, the hashCode method must consistently return the same value, provided no information used in equals comparisons on the object is modified. This value need not remain consistent from one execution of an application to another execution of the same application.
  • If two Objects are equal according to the equals method, then calling the hashCode method on each of the two Objects must produce the same value.
  • It is not required that if two Objects are unequal according to the equals method, then calling the hashCode method on each of the two objects must produce distinct results. However, the programmer should be aware that producing distinct results for unequal objects may improve the performance of hash-based containers.

The default implementation is identity based.

Returns:
a hash code value for this Object

virtual void toStream (std::ostream &out) const
 Output a human-readable description of this Object to the given stream.

coherence::lang::operator<<(std::ostream, Object::View) is defined and will call into the toStream method, to output Objects. If a manged String object is desired, the COH_TO_STRING macro can be used to build up a String from streamable contents.

 Object::View vKey   = ...
 Object::View vValue = ...
 std::cout << vKey << " = " << vValue << std::endl;

 String::Handle hs = COH_TO_STRING(vKey << " = " << vValue);

Parameters:
out the stream used to output the description

virtual String::View getMethodName () const
 Determine the name of the method that this extractor is configured to invoke.
virtual ObjectArray::View getParameters () const
 Return the array of arguments used to invoke the method.

Protected Member Functions

 ReflectionExtractor ()
 Construct an empty ReflectionExtractor (necessary for the PortableObject interface).
 ReflectionExtractor (String::View vsMethod, ObjectArray::View vaParam=NULL)
 Construct a ReflectionExtractor based on a method name and optional parameters.

Protected Attributes

MemberView< Stringm_vsMethod
 The name of the method to invoke.
MemberView< ObjectArraym_vaParam
 The parameter array.

Constructor & Destructor Documentation

ReflectionExtractor ( String::View  vsMethod,
ObjectArray::View  vaParam = NULL 
) [protected]

Construct a ReflectionExtractor based on a method name and optional parameters.

Parameters:
vsMethod the name of the method to invoke via reflection
vaParam the array of arguments to be used in the method invocation; may be NULL


Member Function Documentation

virtual Object::Holder extract ( Object::Holder  ohTarget  )  const [virtual]

Extract the value from the passed object.

The returned value may be NULL.

Parameters:
ohTarget an Object to retrieve the value from
Returns:
the extracted value; NULL is an acceptable value
Exceptions:
ClassCastException if this ValueExtractor is incompatible with the passed object to extract a value from and the implementation requires the passed object to be of a certain type
Exception if this ValueExtractor encounters an exception in the course of extracting the value
IllegalArgumentException if this ValueExtractor cannot handle the passed object for any other reason; an implementor should include a descriptive message

Exceptions:
UnsupportedOperationException always

Implements AbstractExtractor.

virtual String::View getMethodName (  )  const [virtual]

Determine the name of the method that this extractor is configured to invoke.

Returns:
the name of the method to invoke using reflection

virtual ObjectArray::View getParameters (  )  const [virtual]

Return the array of arguments used to invoke the method.

Returns:
the array of arguments used to invoke the method


The documentation for this class was generated from the following file: Copyright (c) 2000-2008 Oracle. All rights reserved.