Package net.sf.cglib.core

Class KeyFactory

java.lang.Object

net.sf.cglib.core.KeyFactory

public abstract class KeyFactory
extends java.lang.Object

Generates classes to handle multi-valued keys, for use in things such as Maps and Sets. Code for equals and hashCode methods follow the the rules laid out in Effective Java by Joshua Bloch.

To generate a KeyFactory, you need to supply an interface which describes the structure of the key. The interface should have a single method named newInstance, which returns an Object. The arguments array can be anything--Objects, primitive values, or single or multi-dimension arrays of either. For example:

     private interface IntStringKey {
         public Object newInstance(int i, String s);
     }
 

Once you have made a KeyFactory, you generate a new key by calling the newInstance method defined by your interface.

     IntStringKey factory = (IntStringKey)KeyFactory.create(IntStringKey.class);
     Object key1 = factory.newInstance(4, "Hello");
     Object key2 = factory.newInstance(4, "World");
 

Note: hashCode equality between two keys key1 and key2 is only guaranteed if key1.equals(key2) and the keys were produced by the same factory.

Version:

$Id: KeyFactory.java,v 1.26 2006/03/05 02:43:19 herbyderby Exp $

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	KeyFactory.Generator

Field Summary

Fields

Modifier and Type	Field	Description
static Customizer	CLASS_BY_NAME
static HashCodeCustomizer	HASH_ASM_TYPE	Type.hashCode() is very expensive as it traverses full descriptor to calculate hash code.
static Customizer	OBJECT_BY_CLASS	Deprecated. this customizer might result in unexpected class leak since key object still holds a strong reference to the Object and class.
static FieldTypeCustomizer	STORE_CLASS_AS_STRING

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	KeyFactory()

Method Summary

Modifier and Type	Method	Description
static KeyFactory	create(java.lang.Class keyInterface)
static KeyFactory	create(java.lang.ClassLoader loader, java.lang.Class keyInterface, Customizer customizer)
static KeyFactory	create(java.lang.ClassLoader loader, java.lang.Class keyInterface, KeyFactoryCustomizer customizer, java.util.List<KeyFactoryCustomizer> next)
static KeyFactory	create(java.lang.Class keyInterface, Customizer customizer)
static KeyFactory	create(java.lang.Class keyInterface, KeyFactoryCustomizer first, java.util.List<KeyFactoryCustomizer> next)

Methods inherited from class java.lang.Object

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

Field Detail

CLASS_BY_NAME

public static final Customizer CLASS_BY_NAME

STORE_CLASS_AS_STRING

public static final FieldTypeCustomizer STORE_CLASS_AS_STRING

HASH_ASM_TYPE

public static final HashCodeCustomizer HASH_ASM_TYPE

Type.hashCode() is very expensive as it traverses full descriptor to calculate hash code. This customizer uses Type.getSort() as a hash code.

OBJECT_BY_CLASS

@Deprecated
public static final Customizer OBJECT_BY_CLASS

Deprecated.

this customizer might result in unexpected class leak since key object still holds a strong reference to the Object and class. It is recommended to have pre-processing method that would strip Objects and represent Classes as Strings

Constructor Detail

KeyFactory

protected KeyFactory()

Method Detail

create

public static KeyFactory create(java.lang.Class keyInterface)

create

public static KeyFactory create(java.lang.Class keyInterface,
                                Customizer customizer)

create

public static KeyFactory create(java.lang.Class keyInterface,
                                KeyFactoryCustomizer first,
                                java.util.List<KeyFactoryCustomizer> next)

create

public static KeyFactory create(java.lang.ClassLoader loader,
                                java.lang.Class keyInterface,
                                Customizer customizer)

create

public static KeyFactory create(java.lang.ClassLoader loader,
                                java.lang.Class keyInterface,
                                KeyFactoryCustomizer customizer,
                                java.util.List<KeyFactoryCustomizer> next)