#include <coherence/util/extractor/KeyExtractor.hpp>
Inherits AbstractExtractor.
The major difference between the KeyExtractor and a standard ReflectionExtractor is that when used in various EntryFilter implementations it forces the evaluation of entry keys rather than entry values.
For example, consider a key object that consists of two properties: "FirstName" and "LastName". To retrieve all keys that have a value of the "LastName" property equal to "Smith", the following query could be used:
ValueExtractor::View extractor = KeyExtractor::create("getLastName"); Set::View setKeys = cache->keySet(EqualsFilter::create(extractor, "Smith"));
As of Coherence 3.5, the same effect can be achieved for subclasses of the AbstractExtractor, for example:
ValueExtractor::View vExtractor = ReflectionExtractor::create("getLastName", NULL, AbstractExtractor::KEY); Set::View setKeys = cache->keySet(EqualsFilter::create(vExtractor, "Smith"));
Public Types | |
typedef spec::Handle | Handle |
KeyExtractor Handle definition. | |
typedef spec::View | View |
KeyExtractor View definition. | |
typedef spec::Holder | Holder |
KeyExtractor Holder definition. | |
Public Member Functions | |
virtual Object::Holder | extract (Object::Holder ohTarget) const |
virtual void | readExternal (PofReader::Handle hIn) |
virtual void | writeExternal (PofWriter::Handle hOut) const |
virtual bool | equals (Object::View v) const |
virtual size32_t | hashCode () const |
virtual TypedHandle < const String > | toString () const |
virtual ValueExtractor::View | getExtractor () const |
Obtain the underlying ValueExtractor. | |
Protected Member Functions | |
KeyExtractor () | |
Create and return a Handle to a new Object instance. | |
KeyExtractor (ValueExtractor::View vExtractor) | |
Construct a KeyExtractor based on a specified ValueExtractor. | |
Protected Attributes | |
MemberView < ValueExtractor > | m_vExtractor |
The underlying ValueExtractor. |
KeyExtractor | ( | ValueExtractor::View | vExtractor | ) | [protected] |
Construct a KeyExtractor based on a specified ValueExtractor.
vExtractor | the underlying ValueExtractor |
virtual ValueExtractor::View getExtractor | ( | ) | const [virtual] |
Obtain the underlying ValueExtractor.