public class CaseInsensitiveMap extends AbstractHashedMap implements java.io.Serializable, java.lang.Cloneable
Map
.
Before keys are added to the map or compared to other existing keys, they are converted to all lowercase in a locale-independent fashion by using information from the Unicode data file.
Null keys are supported.
The keySet()
method returns all lowercase keys, or nulls.
Example:
Map map = new CaseInsensitiveMap();
map.put("One", "One");
map.put("Two", "Two");
map.put(null, "Three");
map.put("one", "Four");
creates a CaseInsensitiveMap
with three entries.map.get(null)
returns "Three"
and map.get("ONE")
returns "Four".
The Set
returned by keySet()
equals {"one", "two", null}.
Note that CaseInsensitiveMap 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.synchronizedMap(Map)
. This class may throw
exceptions when accessed by concurrent threads without synchronization.
AbstractHashedMap.EntrySet, AbstractHashedMap.EntrySetIterator, AbstractHashedMap.HashEntry, AbstractHashedMap.HashIterator, AbstractHashedMap.HashMapIterator, AbstractHashedMap.KeySet, AbstractHashedMap.KeySetIterator, AbstractHashedMap.Values, AbstractHashedMap.ValuesIterator
Modifier and Type | Field and Description |
---|---|
private static long |
serialVersionUID
Serialisation version
|
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 and Description |
---|
CaseInsensitiveMap()
Constructs a new empty map with default size and load factor.
|
CaseInsensitiveMap(int initialCapacity)
Constructs a new, empty map with the specified initial capacity.
|
CaseInsensitiveMap(int initialCapacity,
float loadFactor)
Constructs a new, empty map with the specified initial capacity and
load factor.
|
CaseInsensitiveMap(java.util.Map map)
Constructor copying elements from another map.
|
Modifier and Type | Method and Description |
---|---|
java.lang.Object |
clone()
Clones the map without cloning the keys or values.
|
protected java.lang.Object |
convertKey(java.lang.Object key)
Overrides convertKey() from
AbstractHashedMap to convert keys to
lower case. |
private void |
readObject(java.io.ObjectInputStream in)
Read the map in using a custom routine.
|
private void |
writeObject(java.io.ObjectOutputStream out)
Write the map out using a custom routine.
|
addEntry, addMapping, calculateNewCapacity, calculateThreshold, checkCapacity, clear, containsKey, containsValue, createEntry, createEntrySetIterator, createKeySetIterator, createValuesIterator, destroyEntry, doReadObject, doWriteObject, ensureCapacity, entryHashCode, entryKey, entryNext, entrySet, entryValue, equals, get, getEntry, hash, hashCode, hashIndex, init, isEmpty, isEqualKey, isEqualValue, keySet, mapIterator, put, putAll, remove, removeEntry, removeMapping, reuseEntry, size, toString, updateEntry, values
private static final long serialVersionUID
public CaseInsensitiveMap()
public CaseInsensitiveMap(int initialCapacity)
initialCapacity
- the initial capacityjava.lang.IllegalArgumentException
- if the initial capacity is less than onepublic CaseInsensitiveMap(int initialCapacity, float loadFactor)
initialCapacity
- the initial capacityloadFactor
- the load factorjava.lang.IllegalArgumentException
- if the initial capacity is less than onejava.lang.IllegalArgumentException
- if the load factor is less than zeropublic CaseInsensitiveMap(java.util.Map map)
Keys will be converted to lower case strings, which may cause some entries to be removed (if string representation of keys differ only by character case).
map
- the map to copyjava.lang.NullPointerException
- if the map is nullprotected java.lang.Object convertKey(java.lang.Object key)
AbstractHashedMap
to convert keys to
lower case.
Returns AbstractHashedMap.NULL
if key is null.
convertKey
in class AbstractHashedMap
key
- the key convertpublic java.lang.Object clone()
clone
in class AbstractHashedMap
private void writeObject(java.io.ObjectOutputStream out) throws java.io.IOException
java.io.IOException
private void readObject(java.io.ObjectInputStream in) throws java.io.IOException, java.lang.ClassNotFoundException
java.io.IOException
java.lang.ClassNotFoundException