com.mchange.v2.coalesce
Class CoalescerFactory

java.lang.Object
  extended by com.mchange.v2.coalesce.CoalescerFactory

public final class CoalescerFactory
extends Object


Constructor Summary
CoalescerFactory()
           
 
Method Summary
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.