com.mchange.v2.coalesce

Class CoalescerFactory

java.lang.Object

com.mchange.v2.coalesce.CoalescerFactory

public final class CoalescerFactory
extends java.lang.Object

Constructor Summary

Constructors

Constructor and Description
CoalescerFactory()

Method Summary

Modifier and Type	Method and Description
static Coalescer	createCoalescer() Creates a "Coalescer" that coalesces Objects according to their equals() method.
static Coalescer	createCoalescer(boolean weak, boolean synced) Creates a "Coalescer" that coalesces Objects according to their equals() method.
static Coalescer	createCoalescer(CoalesceChecker cc, boolean weak, boolean synced) Creates a "Coalescer" that coalesces Objects according to the checkCoalesce() method of a "CoalesceChecker".

Methods inherited from class java.lang.Object

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

Constructor Detail

CoalescerFactory

public CoalescerFactory()

Method Detail

createCoalescer

public static Coalescer createCoalescer()

Creates a "Coalescer" that coalesces Objects according to their equals() method. Given a set of n Objects among whom equals() would return true, calling coalescer.coalesce() in any order on any sequence of these Objects will always return a single "canonical" instance.

This method creates a weak, synchronized coalesecer, safe for use by multiple Threads.

createCoalescer

public static Coalescer createCoalescer(boolean weak,
                                        boolean synced)

Creates a "Coalescer" that coalesces Objects according to their equals() method. Given a set of n Objects among whom equals() would return true, calling coalescer.coalesce() in any order on any sequence of these Objects will always return a single "canonical" instance.

Parameters:

weak - if true, the Coalescer will use WeakReferences to hold its canonical instances, allowing them to be garbage collected if they are nowhere in use.

synced - if true, access to the Coalescer will be automatically synchronized. if set to false, then users must manually synchronize access.

createCoalescer

public static Coalescer createCoalescer(CoalesceChecker cc,
                                        boolean weak,
                                        boolean synced)

Creates a "Coalescer" that coalesces Objects according to the checkCoalesce() method of a "CoalesceChecker". Given a set of n Objects among whom calling cc.checkCoalesce() on any pair would return true, calling coalescer.coalesce() in any order on any sequence of these Objects will always return a single "canonical" instance. This allows one to define immutable value Objects whose equals() method is a mere identity test -- one can use a Coalescer in a factory method to ensure that no two instances with the same values are made available to clients.

Parameters:

cc - CoalesceChecker that will be used to determine whether two objects are equivalent and can be coalesced. [If cc is null, then two objects will be coalesced iff o1.equals( o2 ).]

weak - if true, the Coalescer will use WeakReferences to hold its canonical instances, allowing them to be garbage collected if they are nowhere in use.

synced - if true, access to the Coalescer will be automatically synchronized. if set to false, then users must manually synchronize access.