public class LinkedMap<K,V> extends AbstractLinkedMap<K ,V> implements Serializable , Cloneable
Map implementation that maintains the order of the entries. In this implementation order is maintained by original insertion.
This implementation improves on the JDK1.4 LinkedHashMap by adding the MapIterator functionality, additional convenience methods and allowing bidirectional iteration. It also implements OrderedMap. In addition, non-interface methods are provided to access the map by index.
The orderedMapIterator() method provides direct access to a bidirectional iterator. The iterators from the other views can also be cast to OrderedIterator if required.
All the available iterators can be reset back to the start by casting to ResettableIterator and calling reset().
The implementation is also designed to be subclassed, with lots of useful methods exposed.
Note that LinkedMap is not synchronized and is not thread-safe. If you wish to use this map from multiple threads concurrently, you must use appropriate synchronization. The simplest approach is to wrap this map using Collections. This class may throw exceptions when accessed by concurrent threads without synchronization.
AbstractLinkedMap.EntrySetIterator <K,V>, AbstractLinkedMap.KeySetIterator <K>, AbstractLinkedMap.LinkEntry <K,V>, AbstractLinkedMap.LinkIterator <K,V>, AbstractLinkedMap.LinkMapIterator <K,V>, AbstractLinkedMap.ValuesIterator <V> AbstractHashedMap.EntrySet <K,V>, AbstractHashedMap.HashEntry <K,V>, AbstractHashedMap.HashIterator <K,V>, AbstractHashedMap.HashMapIterator <K,V>, AbstractHashedMap.KeySet <K>, AbstractHashedMap.Values <V> AbstractMap.SimpleEntry <K,V>, AbstractMap.SimpleImmutableEntry <K,V> DEFAULT_CAPACITY, DEFAULT_LOAD_FACTOR, DEFAULT_THRESHOLD, GETKEY_INVALID, GETVALUE_INVALID, MAXIMUM_CAPACITY, NO_NEXT_ENTRY, NO_PREVIOUS_ENTRY, NULL, REMOVE_INVALID, SETVALUE_INVALID| Constructor and Description |
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LinkedMap()
Constructs a new empty map with default size and load factor.
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LinkedMap(int initialCapacity)
Constructs a new, empty map with the specified initial capacity.
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LinkedMap(int initialCapacity, float loadFactor)
Constructs a new, empty map with the specified initial capacity and load factor.
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LinkedMap(Map
Constructor copying elements from another map.
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| Modifier and Type | Method and Description |
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List |
asList()
Gets an unmodifiable List view of the keys.
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LinkedMap |
clone()
Clones the map without cloning the keys or values.
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K |
get(int index)
Gets the key at the specified index.
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V |
getValue(int index)
Gets the value at the specified index.
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int |
indexOf(Object
Gets the index of the specified key.
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V |
remove(int index)
Removes the element at the specified index.
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addEntry, clear, containsValue, createEntry, createEntrySetIterator, createKeySetIterator, createValuesIterator, entryAfter, entryBefore, firstKey, getEntry, getEntry, init, lastKey, mapIterator, nextKey, previousKey, removeEntryaddMapping, calculateNewCapacity, calculateThreshold, checkCapacity, containsKey, convertKey, destroyEntry, doReadObject, doWriteObject, ensureCapacity, entryHashCode, entryKey, entryNext, entrySet, entryValue, equals, get, hash, hashCode, hashIndex, isEmpty, isEqualKey, isEqualValue, keySet, put, putAll, remove, removeMapping, reuseEntry, size, toString, updateEntry, valuesfinalize, getClass, notify, notifyAll, wait, wait, waitcompute, computeIfAbsent, computeIfPresent, containsKey, entrySet, equals, forEach, get, getOrDefault, hashCode, isEmpty, keySet, merge, put, putAll, putIfAbsent, remove, remove, replace, replace, replaceAll, size, valuespublic LinkedMap()
public LinkedMap(int initialCapacity)
initialCapacity - the initial capacity
IllegalArgumentException - if the initial capacity is negative
public LinkedMap(int initialCapacity,
float loadFactor)
initialCapacity - the initial capacity
loadFactor - the load factor
IllegalArgumentException - if the initial capacity is negative
IllegalArgumentException - if the load factor is less than zero
public LinkedMap(Map<? extends K ,? extends V> map)
map - the map to copy
NullPointerException - if the map is null
public LinkedMap<K ,V> clone()
clone in class
AbstractHashedMap<K,V>
public K get(int index)
index - the index to retrieve
IndexOutOfBoundsException - if the index is invalid
public V getValue(int index)
index - the index to retrieve
IndexOutOfBoundsException - if the index is invalid
public int indexOf(Objectkey)
key - the key to find the index of
public V remove(int index)
index - the index of the object to remove
key, or
null if none existed
IndexOutOfBoundsException - if the index is invalid
public List<K> asList()
The returned list is unmodifiable because changes to the values of the list (using ListIterator) will effectively remove the value from the list and reinsert that value at the end of the list, which is an unexpected side effect of changing the value of a list. This occurs because changing the key, changes when the mapping is added to the map and thus where it appears in the list.
An alternative to this method is to use AbstractHashedMap.
AbstractHashedMap.keySet()