Package org.apache.commons.collections.map
This package contains implementations of the
Map
,
IterableMap
,
OrderedMap
and
SortedMap
interfaces.
A Map provides a lookup from a key to a value.
A number of implementations also support the new MapIterator interface that enables
simple iteration of map keys and values.
The following implementations are provided:
- CaseInsensitiveMap - map that compares keys in a case insensitive way
- CompositeMap - map that combines multiple maps into a single view
- HashedMap - general purpose HashMap replacement supporting MapIterator
- IdentityMap - map that uses == for comparison instead of equals()
- Flat3Map - designed for good performance at size 3 or less
- LinkedMap - a hash map that maintains insertion order, supporting OrderedMapIterator
- MultiKeyMap - map that provides special methods for using more than one key to access the value
- ReferenceMap - allows the garbage collector to collect keys and values using equals() for comparison
- ReferenceIdentityMap - allows the garbage collector to collect keys and values using == for comparison
- SingletonMap - a fully featured map to hold one key-value pair
- StaticBucketMap - internally synchronized and designed for thread-contentious environments
The following decorators are provided:
- Unmodifiable - ensures the collection cannot be altered
- Predicated - ensures that only elements that are valid according to a predicate can be added
- Typed - ensures that only elements that are of a specific type can be added
- Transformed - transforms each element added
- FixedSize - ensures that the size of the map cannot change
- Lazy - creates objects in the map on demand
- ListOrdered - ensures that insertion order is retained
-
Interface Summary Interface Description CompositeMap.MapMutator This interface allows definition for all of the indeterminate mutators in a CompositeMap, as well as providing a hook for callbacks on key collisions. -
Class Summary Class Description AbstractHashedMap An abstract implementation of a hash-based map which provides numerous points for subclasses to override.AbstractHashedMap.EntrySet EntrySet implementation.AbstractHashedMap.EntrySetIterator EntrySet iterator.AbstractHashedMap.HashEntry HashEntry used to store the data.AbstractHashedMap.HashIterator Base IteratorAbstractHashedMap.HashMapIterator MapIterator implementation.AbstractHashedMap.KeySet KeySet implementation.AbstractHashedMap.KeySetIterator KeySet iterator.AbstractHashedMap.Values Values implementation.AbstractHashedMap.ValuesIterator Values iterator.AbstractInputCheckedMapDecorator An abstract base class that simplifies the task of creating map decorators.AbstractInputCheckedMapDecorator.EntrySet Implementation of an entry set that checks additions via setValue.AbstractInputCheckedMapDecorator.EntrySetIterator Implementation of an entry set iterator that checks additions via setValue.AbstractInputCheckedMapDecorator.MapEntry Implementation of a map entry that checks additions via setValue.AbstractLinkedMap An abstract implementation of a hash-based map that links entries to create an ordered map and which provides numerous points for subclasses to override.AbstractLinkedMap.EntrySetIterator EntrySet iterator.AbstractLinkedMap.KeySetIterator KeySet iterator.AbstractLinkedMap.LinkEntry LinkEntry that stores the data.AbstractLinkedMap.LinkIterator Base Iterator that iterates in link order.AbstractLinkedMap.LinkMapIterator MapIterator implementation.AbstractLinkedMap.ValuesIterator Values iterator.AbstractMapDecorator Provides a base decorator that enables additional functionality to be added to a Map via decoration.AbstractOrderedMapDecorator Provides a base decorator that enables additional functionality to be added to an OrderedMap via decoration.AbstractReferenceMap An abstract implementation of a hash-based map that allows the entries to be removed by the garbage collector.AbstractReferenceMap.ReferenceEntry A MapEntry implementation for the map.AbstractReferenceMap.ReferenceEntrySet EntrySet implementation.AbstractReferenceMap.ReferenceEntrySetIterator The EntrySet iterator.AbstractReferenceMap.ReferenceKeySet KeySet implementation.AbstractReferenceMap.ReferenceKeySetIterator The keySet iterator.AbstractReferenceMap.ReferenceMapIterator The MapIterator implementation.AbstractReferenceMap.ReferenceValues Values implementation.AbstractReferenceMap.ReferenceValuesIterator The values iterator.AbstractReferenceMap.SoftRef A soft reference holder.AbstractReferenceMap.WeakRef A weak reference holder.AbstractSortedMapDecorator Provides a base decorator that enables additional functionality to be added to a Map via decoration.CaseInsensitiveMap A case-insensitiveMap
.CompositeMap Decorates a map of other maps to provide a single unified view.DefaultedMap Decorates anotherMap
returning a default value if the map does not contain the requested key.FixedSizeMap Decorates anotherMap
to fix the size, preventing add/remove.FixedSizeSortedMap Decorates anotherSortedMap
to fix the size blocking add/remove.Flat3Map AMap
implementation that stores data in simple fields until the size is greater than 3.Flat3Map.EntrySet EntrySetFlat3Map.EntrySetIterator EntrySetIterator and MapEntryFlat3Map.FlatMapIterator FlatMapIteratorFlat3Map.KeySet KeySetFlat3Map.KeySetIterator KeySetIteratorFlat3Map.Values ValuesFlat3Map.ValuesIterator ValuesIteratorHashedMap AMap
implementation that is a general purpose alternative toHashMap
.IdentityMap AMap
implementation that matches keys and values based on==
notequals()
.IdentityMap.IdentityEntry HashEntryLazyMap Decorates anotherMap
to create objects in the map on demand.LazySortedMap Decorates anotherSortedMap
to create objects in the map on demand.LinkedMap AMap
implementation that maintains the order of the entries.LinkedMap.LinkedMapList List view of map.ListOrderedMap Decorates aMap
to ensure that the order of addition is retained using aList
to maintain order.ListOrderedMap.EntrySetView ListOrderedMap.KeySetView ListOrderedMap.ListOrderedIterator ListOrderedMap.ListOrderedMapEntry ListOrderedMap.ListOrderedMapIterator ListOrderedMap.ValuesView LRUMap AMap
implementation with a fixed maximum size which removes the least recently used entry if an entry is added when full.MultiKeyMap AMap
implementation that uses multiple keys to map the value.MultiValueMap A MultiValueMap decorates another map, allowing it to have more than one value for a key.MultiValueMap.ReflectionFactory Inner class that provides a simple reflection factory.PredicatedMap Decorates anotherMap
to validate that additions match a specified predicate.PredicatedSortedMap Decorates anotherSortedMap
to validate that additions match a specified predicate.ReferenceIdentityMap AMap
implementation that allows mappings to be removed by the garbage collector and matches keys and values based on==
notequals()
.ReferenceMap AMap
implementation that allows mappings to be removed by the garbage collector.SingletonMap AMap
implementation that holds a single item and is fixed size.SingletonMap.SingletonMapIterator SingletonMapIterator.SingletonMap.SingletonValues Values implementation for the SingletonMap.StaticBucketMap A StaticBucketMap is an efficient, thread-safe implementation ofjava.util.Map
that performs well in in a highly thread-contentious environment.StaticBucketMap.Lock The lock object, which also includes a count of the nodes in this lock.StaticBucketMap.Node The Map.Entry for the StaticBucketMap.TransformedMap Decorates anotherMap
to transform objects that are added.TransformedSortedMap Decorates anotherSortedMap
to transform objects that are added.TypedMap Decorates anotherMap
to validate that elements added are of a specific type.TypedSortedMap Decorates anotherSortedMap
to validate that elements added are of a specific type.UnmodifiableEntrySet Decorates a map entrySet
to ensure it can't be altered.UnmodifiableEntrySet.UnmodifiableEntry Implementation of a map entry that is unmodifiable.UnmodifiableEntrySet.UnmodifiableEntrySetIterator Implementation of an entry set iterator.UnmodifiableMap Decorates anotherMap
to ensure it can't be altered.UnmodifiableOrderedMap Decorates anotherOrderedMap
to ensure it can't be altered.UnmodifiableSortedMap Decorates anotherSortedMap
to ensure it can't be altered.