wt.fc
Class ReferenceResolver

java.lang.Object
  wt.fc.ReferenceResolver

public final class ReferenceResolver

extends Object

Uses introspection and reflection to find the best matching reference class for a given Persistable class.

The public APIs are all thread-safe.

Field Summary

private static String	CLASSNAME
private static boolean	DEBUG
static Map	DEFAULT_OVERRIDES
private static DebugWriter	LOG
private static Object	NO_MATCH
private HashMap	persistableTypesToReferenceTypes
private Map	referenceTypesToPersistableFactoryMethods
private Map	referenceTypesToQueryKeyFactoryMethods

Constructor Summary

ReferenceResolver(Class root_class)
Creates a ReferenceResolver for all descendents of the given reference class

ReferenceResolver(Class root_class, Map overrides)
Creates a ReferenceResolver for all descendents of the given reference class

Method Summary

private void	addTarget(ClassInfo info) Called by the constructor to build up the persistableTypesToReferenceTypes map
(package private) static Method	getFactoryMethod(Class object_class, Class parameter_class) Tries to use reflection to get a system-generated factory method for the given object type that has the given parameter type.
(package private) static String	getFactoryMethodName(Class reference_class) Gets the system-generated factory method for the given class
(package private) static Class	getPersistableTypeByIntrospection(ClassInfo info) Tries to use introspection to get the Persistsble object type that corresponds to the given reference type, by looking at the references CONSTRAINED_TYPE property
WTReference	getReference(Persistable p) Create a reference to the given Persistable
WTReference	getReference(QueryKey query_key) Create a reference to the given QueryKey
Class	getReferenceClass(Class persistable_class) Get the Class of WTReference that should be used for instances of the given Persistable class.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

CLASSNAME

private static final String CLASSNAME

DEBUG

private static final boolean DEBUG

LOG

private static final DebugWriter LOG

NO_MATCH

private static final Object NO_MATCH

persistableTypesToReferenceTypes

private volatile HashMap persistableTypesToReferenceTypes

referenceTypesToPersistableFactoryMethods

private final Map referenceTypesToPersistableFactoryMethods

referenceTypesToQueryKeyFactoryMethods

private final Map referenceTypesToQueryKeyFactoryMethods

DEFAULT_OVERRIDES

public static final Map DEFAULT_OVERRIDES

Constructor Detail

ReferenceResolver

public ReferenceResolver(Class root_class)

Creates a ReferenceResolver for all descendents of the given reference class

Parameters:

root_class - The root class that all references resolved by this instance will be subclasses of

ReferenceResolver

public ReferenceResolver(Class root_class,
                         Map overrides)

Creates a ReferenceResolver for all descendents of the given reference class

Parameters:

root_class - The root class that all references resolved by this instance will be subclasses of

overrides - Mapping of persistable types to reference types that will override what would have been found via introspection or reflection

Method Detail

getReference

public WTReference getReference(Persistable p)

Create a reference to the given Persistable

Parameters:

p -

Returns:

WTReference

getReference

public WTReference getReference(QueryKey query_key)

Create a reference to the given QueryKey

Parameters:

query_key -

Returns:

WTReference

getReferenceClass

public Class getReferenceClass(Class persistable_class)

Get the Class of WTReference that should be used for instances of the given Persistable class.

The implementation uses a copy-on-write strategy to keep this method from paying synchronization costs

Parameters:

persistable_class - The class of Persistable to find a reference class for.

Returns:

The corresponding subclass of ObjectReference, or null if one can't be found

addTarget

private void addTarget(ClassInfo info)
                throws WTException

Called by the constructor to build up the persistableTypesToReferenceTypes map

Throws:

WTException

getPersistableTypeByIntrospection

static Class getPersistableTypeByIntrospection(ClassInfo info)
                                        throws WTException

Tries to use introspection to get the Persistsble object type that corresponds to the given reference type, by looking at the references CONSTRAINED_TYPE property

Returns:

The matching Persistable Class, or null if it couldn't be found

Throws:

WTException

getFactoryMethod

static Method getFactoryMethod(Class object_class,
                               Class parameter_class)

Tries to use reflection to get a system-generated factory method for the given object type that has the given parameter type.

Parameters:

object_class - The class to find a factory method for

parameter_class - The class of parameter the method should have

Returns:

The matching factory method, or null if it couldn't be found

getFactoryMethodName

static String getFactoryMethodName(Class reference_class)

Gets the system-generated factory method for the given class

Parameters:

reference_class - A Class that ObjectReference is assignable from

Returns:

String