oracle.adfnmc.java.util
Class LinkedHashMap

java.lang.Object
  oracle.adfnmc.java.util.AbstractMap
      oracle.adfnmc.java.util.HashMap
          oracle.adfnmc.java.util.LinkedHashMap

All Implemented Interfaces:

Serializable, Cloneable, Map

public class LinkedHashMap
extends HashMap

LinkedHashMap is a variant on HashMap. Its entries are kept in a doubly-linked list. The iteration order is, by default, the order in which keys were inserted.

If the three argument constructor is used, and order is specified as true, the iteration would be in the order that entries were accessed. The access order gets affected by put(), get(), putAll() operations, but not by operations on the collection views.

Null elements are allowed, and all the optional Map operations are supported.

Since:

1.4

Constructor Summary

LinkedHashMap()
Constructs a new empty instance of LinkedHashMap.

LinkedHashMap(int s)
Constructor with specified size.

LinkedHashMap(int s, float lf)
Constructor with specified size and load factor.

LinkedHashMap(int s, float lf, boolean order)
Constructor with specified size, load factor and access order

LinkedHashMap(Map m)
Constructor with input map

Method Summary

void	clear() Removes all mappings from this HashMap, leaving it empty.
java.lang.Object	clone() Answers a new HashMap with the same mappings and size as this HashMap.
boolean	containsValue(java.lang.Object value) Searches this map for the specified value.
Set	entrySet() Answers a Set of the mappings contained in this HashMap.
java.lang.Object	get(java.lang.Object key) Retrieve the map value corresponding to the given key.
Set	keySet() Answers a Set of the keys contained in this HashMap.
java.lang.Object	put(java.lang.Object key, java.lang.Object value) Set the mapped value for the given key to the given value.
java.lang.Object	remove(java.lang.Object key) Remove the entry corresponding to the given key.
protected boolean	removeEldestEntry(Map.Entry eldest) This method is queried from the put and putAll methods to check if the eldest member of the map should be deleted before adding the new member.
Collection	values() Answers a Collection of the values contained in this HashMap.

Methods inherited from class oracle.adfnmc.java.util.HashMap

containsKey, isEmpty, putAll, putAll, size

Methods inherited from class oracle.adfnmc.java.util.AbstractMap

equals, hashCode, toString

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface oracle.adfnmc.java.util.Map

equals, hashCode

Constructor Detail

LinkedHashMap

public LinkedHashMap()

Constructs a new empty instance of LinkedHashMap.

LinkedHashMap

public LinkedHashMap(int s)

Constructor with specified size.

Parameters:

s - Size of LinkedHashMap required

LinkedHashMap

public LinkedHashMap(int s,
                     float lf)

Constructor with specified size and load factor.

Parameters:

s - Size of LinkedHashMap required

lf - Load factor

LinkedHashMap

public LinkedHashMap(int s,
                     float lf,
                     boolean order)

Constructor with specified size, load factor and access order

Parameters:

s - Size of LinkedHashmap required

lf - Load factor

order - If true indicates that traversal order should begin with most recently accessed

LinkedHashMap

public LinkedHashMap(Map m)

Constructor with input map

Parameters:

m - Input map

Method Detail

containsValue

public boolean containsValue(java.lang.Object value)

Searches this map for the specified value.

Specified by:

containsValue in interface Map

Overrides:

containsValue in class HashMap

Parameters:

value - the object to search for

Returns:

true if value is a value of this HashMap, false otherwise

get

public java.lang.Object get(java.lang.Object key)

Retrieve the map value corresponding to the given key.

Specified by:

get in interface Map

Overrides:

get in class HashMap

Parameters:

key - Key value

Returns:

mapped value or null if the key is not in the map

put

public java.lang.Object put(java.lang.Object key,
                            java.lang.Object value)

Set the mapped value for the given key to the given value.

Specified by:

put in interface Map

Overrides:

put in class HashMap

Parameters:

key - Key value

value - New mapped value

Returns:

The old value if the key was already in the map or null otherwise.

entrySet

public Set entrySet()

Answers a Set of the mappings contained in this HashMap. Each element in the set is a Map.Entry. The set is backed by this HashMap so changes to one are reflected by the other. The set does not support adding.

Specified by:

entrySet in interface Map

Overrides:

entrySet in class HashMap

Returns:

a Set of the mappings

keySet

public Set keySet()

Answers a Set of the keys contained in this HashMap. The set is backed by this HashMap so changes to one are reflected by the other. The set does not support adding.

Specified by:

keySet in interface Map

Overrides:

keySet in class HashMap

Returns:

a Set of the keys

values

public Collection values()

Answers a Collection of the values contained in this HashMap. The collection is backed by this HashMap so changes to one are reflected by the other. The collection does not support adding.

Specified by:

values in interface Map

Overrides:

values in class HashMap

Returns:

a Collection of the values

remove

public java.lang.Object remove(java.lang.Object key)

Remove the entry corresponding to the given key.

Specified by:

remove in interface Map

Overrides:

remove in class HashMap

Parameters:

key - the key

Returns:

the value associated with the key or null if the key was no in the map

removeEldestEntry

protected boolean removeEldestEntry(Map.Entry eldest)

This method is queried from the put and putAll methods to check if the eldest member of the map should be deleted before adding the new member. If this map was created with accessOrder = true, then the result of removeEldesrEntry is assumed to be false.

Parameters:

eldest -

Returns:

true if the eldest member should be removed

clear

public void clear()

Removes all mappings from this HashMap, leaving it empty.

Specified by:

clear in interface Map

Overrides:

clear in class HashMap

See Also:

HashMap.isEmpty(), HashMap.size()

clone

public java.lang.Object clone()

Description copied from class: HashMap

Answers a new HashMap with the same mappings and size as this HashMap.

Overrides:

clone in class HashMap

Returns:

a shallow copy of this HashMap

See Also:

Cloneable