org.deduced.utilities
Class IdentityReferenceMap

java.lang.Object
  java.util.AbstractMap
      org.apache.commons.collections.map.AbstractHashedMap
          org.apache.commons.collections.map.AbstractReferenceMap
              org.apache.commons.collections.map.ReferenceMap
                  org.deduced.utilities.IdentityReferenceMap

All Implemented Interfaces:

java.io.Serializable, java.util.Map, org.apache.commons.collections.IterableMap

public class IdentityReferenceMap
extends org.apache.commons.collections.map.ReferenceMap

IdentityReferenceMap is used to create a map where the developer can control the way keys and values are referenced and how keys and values are checked for equality. For the reference type on keys and values, see the documentation for ReferenceMap. During construction, boolean flags indicate if keys and values should be compared with the equal function call or the "==" operator.

Author:

Steve McDuff

See Also:

Serialized Form

Nested Class Summary

protected static class

IdentityReferenceMap.IdentityReferenceEntry IdentityReferenceEntry is used to create hash entries in the map.

Nested classes/interfaces inherited from class org.apache.commons.collections.map.AbstractReferenceMap

org.apache.commons.collections.map.AbstractReferenceMap.ReferenceEntry

Nested classes/interfaces inherited from class org.apache.commons.collections.map.AbstractHashedMap

org.apache.commons.collections.map.AbstractHashedMap.EntrySet, org.apache.commons.collections.map.AbstractHashedMap.EntrySetIterator, org.apache.commons.collections.map.AbstractHashedMap.HashEntry, org.apache.commons.collections.map.AbstractHashedMap.HashIterator, org.apache.commons.collections.map.AbstractHashedMap.HashMapIterator, org.apache.commons.collections.map.AbstractHashedMap.KeySet, org.apache.commons.collections.map.AbstractHashedMap.KeySetIterator, org.apache.commons.collections.map.AbstractHashedMap.Values, org.apache.commons.collections.map.AbstractHashedMap.ValuesIterator

Nested classes/interfaces inherited from class java.util.AbstractMap

java.util.AbstractMap.SimpleEntry<K,V>, java.util.AbstractMap.SimpleImmutableEntry<K,V>

Nested classes/interfaces inherited from interface java.util.Map

java.util.Map.Entry<K,V>

Field Summary

private boolean	keyByInstance if true, keys are compared with the "==" operator.
private static long	serialVersionUID serial ID
private boolean	valueByInstance if true, values are compared with the "==" operator.

Fields inherited from class org.apache.commons.collections.map.AbstractReferenceMap

HARD, keyType, purgeValues, SOFT, valueType, WEAK

Fields inherited from class org.apache.commons.collections.map.AbstractHashedMap

data, DEFAULT_CAPACITY, DEFAULT_LOAD_FACTOR, DEFAULT_THRESHOLD, entrySet, GETKEY_INVALID, GETVALUE_INVALID, keySet, loadFactor, MAXIMUM_CAPACITY, modCount, NO_NEXT_ENTRY, NO_PREVIOUS_ENTRY, NULL, REMOVE_INVALID, SETVALUE_INVALID, size, threshold, values

Constructor Summary

IdentityReferenceMap(boolean setKeyByInstance, boolean setValueByInstance, int setKeyType, int setValueType)
IdentityReferenceMap constructor

IdentityReferenceMap(boolean setKeyByInstance, boolean setValueByInstance, int setKeyType, int setValueType, int capacity, float setLoadFactor, boolean setPurgeValues)
IdentityReferenceMap constructor

Method Summary

protected org.apache.commons.collections.map.AbstractHashedMap.HashEntry	createEntry(org.apache.commons.collections.map.AbstractHashedMap.HashEntry next, int hashCode, java.lang.Object key, java.lang.Object value) Creates an entry to store the data.
boolean	equals(java.lang.Object obj) Compares this map with another.
int	getKeyType() getKeyType
int	getValueType() getValueType
protected int	hash(java.lang.Object key) Gets the hash code for the key specified.
int	hashCode() (non-Javadoc)
protected int	hashKey(java.lang.Object key) hash a key.
protected int	hashValue(java.lang.Object value) hash a value.
protected boolean	isEqualKey(java.lang.Object key1, java.lang.Object key2) Compares two keys for equals.
protected boolean	isEqualValue(java.lang.Object value1, java.lang.Object value2) Compares two values for equals.
boolean	isKeyByInstance() is Key By Instance
boolean	isValueByInstance() is Value By Instance

Methods inherited from class org.apache.commons.collections.map.AbstractReferenceMap

clear, containsKey, containsValue, createEntrySetIterator, createKeySetIterator, createValuesIterator, doReadObject, doWriteObject, entrySet, get, getEntry, hashEntry, init, isEmpty, keySet, mapIterator, purge, purge, purgeBeforeRead, purgeBeforeWrite, put, remove, size, values

Methods inherited from class org.apache.commons.collections.map.AbstractHashedMap

addEntry, addMapping, calculateNewCapacity, calculateThreshold, checkCapacity, clone, convertKey, destroyEntry, ensureCapacity, entryHashCode, entryKey, entryNext, entryValue, hashIndex, putAll, removeEntry, removeMapping, reuseEntry, toString, updateEntry

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

serialVersionUID

private static final long serialVersionUID

serial ID

See Also:

Constant Field Values

keyByInstance

private final boolean keyByInstance

if true, keys are compared with the "==" operator. If false, they are compared with a call to the equal method.

valueByInstance

private final boolean valueByInstance

if true, values are compared with the "==" operator. If false, they are compared with a call to the equal method.

Constructor Detail

IdentityReferenceMap

public IdentityReferenceMap(boolean setKeyByInstance,
                            boolean setValueByInstance,
                            int setKeyType,
                            int setValueType)

IdentityReferenceMap constructor

Parameters:

setKeyByInstance - if true, keys are compared with the "==" operator. If false, they are compared with a call to the equal method.

setValueByInstance - if true, keys are compared with the "==" operator. If false, they are compared with a call to the equal method.

setKeyType - the type of reference to use for keys; must be AbstractReferenceMap.HARD, AbstractReferenceMap.SOFT, AbstractReferenceMap.WEAK

setValueType - the type of reference to use for values; must be AbstractReferenceMap.HARD, AbstractReferenceMap.SOFT, AbstractReferenceMap.WEAK

IdentityReferenceMap

public IdentityReferenceMap(boolean setKeyByInstance,
                            boolean setValueByInstance,
                            int setKeyType,
                            int setValueType,
                            int capacity,
                            float setLoadFactor,
                            boolean setPurgeValues)

IdentityReferenceMap constructor

Parameters:

setKeyByInstance - if true, keys are compared with the "==" operator. If false, they are compared with a call to the equal method.

setValueByInstance - if true, keys are compared with the "==" operator. If false, they are compared with a call to the equal method.

setKeyType - the type of reference to use for keys; must be AbstractReferenceMap.HARD, AbstractReferenceMap.SOFT, AbstractReferenceMap.WEAK

setValueType - the type of reference to use for values; must be AbstractReferenceMap.HARD, AbstractReferenceMap.SOFT, AbstractReferenceMap.WEAK

capacity - the initial capacity for the map

setLoadFactor - the load factor for the map

setPurgeValues - should the value be automatically purged when the key is garbage collected

Method Detail

isKeyByInstance

public boolean isKeyByInstance()

is Key By Instance

Returns:

true if keys are referenced by instance

isValueByInstance

public boolean isValueByInstance()

is Value By Instance

Returns:

true if values are referenced by instance

getValueType

public int getValueType()

getValueType

Returns:

how values are held by the map : AbstractReferenceMap.HARD, AbstractReferenceMap.SOFT, AbstractReferenceMap.WEAK

getKeyType

public int getKeyType()

getKeyType

Returns:

how keys are held by the map : AbstractReferenceMap.HARD, AbstractReferenceMap.SOFT, AbstractReferenceMap.WEAK

hash

protected int hash(java.lang.Object key)

Gets the hash code for the key specified. This implementation uses the identity hash code if keys are by value or the .

Overrides:

hash in class org.apache.commons.collections.map.AbstractHashedMap

Parameters:

key - the key to get a hash code for

Returns:

the hash code

isEqualKey

protected boolean isEqualKey(java.lang.Object key1,
                             java.lang.Object key2)

Compares two keys for equals. This implementation uses ==.

Overrides:

isEqualKey in class org.apache.commons.collections.map.AbstractReferenceMap

Parameters:

key1 - the first key to compare

key2 - the second key to compare

Returns:

true if equal by identity

isEqualValue

protected boolean isEqualValue(java.lang.Object value1,
                               java.lang.Object value2)

Compares two values for equals. This implementation uses ==.

Overrides:

isEqualValue in class org.apache.commons.collections.map.AbstractHashedMap

Parameters:

value1 - the first value to compare

value2 - the second value to compare

Returns:

true if equal by identity

createEntry

protected org.apache.commons.collections.map.AbstractHashedMap.HashEntry createEntry(org.apache.commons.collections.map.AbstractHashedMap.HashEntry next,
                                                                                     int hashCode,
                                                                                     java.lang.Object key,
                                                                                     java.lang.Object value)

Creates an entry to store the data. This implementation creates an IdentityEntry instance.

Overrides:

createEntry in class org.apache.commons.collections.map.AbstractReferenceMap

Parameters:

next - the next entry in sequence

hashCode - the hash code to use

key - the key to store

value - the value to store

Returns:

the newly created entry

hashKey

protected int hashKey(java.lang.Object key)

hash a key. The output will depend on the keyByInstance flag.

Parameters:

key - the key to hash.

Returns:

the key hash code.

hashValue

protected int hashValue(java.lang.Object value)

hash a value. The output will depend on the valueByInstance flag.

Parameters:

value - the value to hash.

Returns:

the value hash code.

equals

public boolean equals(java.lang.Object obj)

Compares this map with another.

Specified by:

equals in interface java.util.Map

Overrides:

equals in class org.apache.commons.collections.map.AbstractHashedMap

Parameters:

obj - the object to compare to

Returns:

true if equal

hashCode

public int hashCode()

(non-Javadoc)

Specified by:

hashCode in interface java.util.Map

Overrides:

hashCode in class org.apache.commons.collections.map.AbstractHashedMap

See Also:

AbstractHashedMap.hashCode()