Package org.pentaho.reporting.libraries.base.util

Class LinkedMap

java.lang.Object

org.pentaho.reporting.libraries.base.util.LinkedMap

All Implemented Interfaces:

Serializable, Cloneable

public class LinkedMap
extends Object
implements Cloneable, Serializable

A fast linked-hashmap that avoids any unneccessay work. It is slightly slower than an ordinary hashmap but faster than a combined hashmap and list-index that would be needed to get this functionality on JDK 1.2. The map is as fast as the LinkedHashMap of JDK 1.4+.

Author:

Thomas Morgner

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected static class	LinkedMap.MapEntry	A cache map entry class holding both the key and value and acting as member of a linked list.

Constructor Summary

Constructors

Constructor	Description
LinkedMap()	Default constructor.
LinkedMap(int initialCapacity, float loadFactor)	Creates a new map with the given initial number of buckets and the given loadfactor.

Method Summary

Modifier and Type	Method	Description
void	clear()	Clears the map and removes all map records.
Object	clone()	Clones this map.
boolean	containsKey(Object key)	Checks, whether the map contains an entry for the key.
Object	get(Object key)	Retrieves the object stored under the given key from the map.
boolean	isEmpty()	Checks whether this collection is empty.
Object[]	keys()	Returns the keys used in this map as array.
Object[]	keys(Object[] data)	Returns the keys used in this map as array.
Object	put(Object key, Object value)	Stores the given value in the map using the provided key.
Object	remove(Object key)	Removes the object stored under the given key from the map.
int	size()	Returns the number of entries in the map.
Object[]	values()	Returns the values used in this map as array.
Object[]	values(Object[] data)	Returns the values used in this map as array.

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

LinkedMap

public LinkedMap()

Default constructor. Creates a map for 16 entries with a default load-factor of 0.75.

LinkedMap

public LinkedMap(int initialCapacity,
                 float loadFactor)

Creates a new map with the given initial number of buckets and the given loadfactor. A load factor greater 1 will always cause hash-collisions, while lower loadfactors reduce the likelyhood of collisions.

Parameters:

initialCapacity - the initial capacity.

loadFactor - the load factor of the bucket-array.

Method Detail

size

public int size()

Returns the number of entries in the map.

Returns:

the number of entries.

put

public Object put(Object key,
                  Object value)

Stores the given value in the map using the provided key. Both key and value can be null.

Parameters:

key - the key.

value - the value to be stored under the key.

Returns:

the previous value stored under this key or null of the entry is new.

get

public Object get(Object key)

Retrieves the object stored under the given key from the map.

Parameters:

key - the key for which a value should be located.

Returns:

the value or null, if the map did not contain a value for the key.

remove

public Object remove(Object key)

Removes the object stored under the given key from the map.

Parameters:

key - the key for which a value should be located.

Returns:

the value or null, if the map did not contain a value for the key.

containsKey

public boolean containsKey(Object key)

Checks, whether the map contains an entry for the key.

Parameters:

key - the key for which a value should be located.

Returns:

true if the map contains a value for the key, false otherwise.

keys

public Object[] keys(Object[] data)

Returns the keys used in this map as array. The keys are returned in the insertation order.

Parameters:

data - the object array that should receive the keys.

Returns:

the array filled with the keys.

keys

public Object[] keys()

Returns the keys used in this map as array. The keys are returned in the insertation order.

Returns:

the array filled with the keys.

values

public Object[] values()

Returns the values used in this map as array. The values are returned in the insertation order.

Returns:

the array filled with the values.

values

public Object[] values(Object[] data)

Returns the values used in this map as array. The values are returned in the insertation order.

Parameters:

data - the object array that should receive the values.

Returns:

the array filled with the values.

clear

public void clear()

Clears the map and removes all map records.

clone

public Object clone()
             throws CloneNotSupportedException

Clones this map.

Overrides:

clone in class Object

Returns:

the cloned map.

Throws:

CloneNotSupportedException

isEmpty

public boolean isEmpty()

Checks whether this collection is empty.

Returns:

true, if the collection is empty, false otherwise.