com.itextpdf.text.pdf
Class LongHashtable

java.lang.Object
  com.itextpdf.text.pdf.LongHashtable

All Implemented Interfaces:

Cloneable

public class LongHashtable
extends Object
implements Cloneable

A hash map that uses primitive ints for the key rather than objects.

Note that this class is for internal optimization purposes only, and may not be supported in future releases of Jakarta Commons Lang. Utilities of this sort may be included in future releases of Jakarta Commons Collections.

Author:

Justin Couch, Alex Chaffee (alex@apache.org), Stephen Colebourne, Bruno Lowagie (change Objects as keys into int values), Paulo Soares (added extra methods)

Constructor Summary

LongHashtable()
Constructs a new, empty hashtable with a default capacity and load factor, which is 20 and 0.75 respectively.

LongHashtable(int initialCapacity)
Constructs a new, empty hashtable with the specified initial capacity and default load factor, which is 0.75.

LongHashtable(int initialCapacity, float loadFactor)
Constructs a new, empty hashtable with the specified initial capacity and the specified load factor.

Method Summary

void	clear() Clears this hashtable so that it contains no keys.
Object	clone()
boolean	contains(long value) Tests if some key maps into the specified value in this hashtable.
boolean	containsKey(long key) Tests if the specified int is a key in this hashtable.
boolean	containsValue(long value) Returns true if this HashMap maps one or more keys to this value.
long	get(long key) Returns the value to which the specified key is mapped in this map.
Iterator<com.itextpdf.text.pdf.LongHashtable.Entry>	getEntryIterator()
long[]	getKeys()
long	getOneKey()
boolean	isEmpty() Tests if this hashtable maps no keys to values.
long	put(long key, long value) Maps the specified key to the specified value in this hashtable.
protected void	rehash() Increases the capacity of and internally reorganizes this hashtable, in order to accommodate and access its entries more efficiently.
long	remove(long key) Removes the key (and its corresponding value) from this hashtable.
int	size() Returns the number of keys in this hashtable.
long[]	toOrderedKeys()

Methods inherited from class java.lang.Object

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

Constructor Detail

LongHashtable

public LongHashtable()

Constructs a new, empty hashtable with a default capacity and load factor, which is 20 and 0.75 respectively.

LongHashtable

public LongHashtable(int initialCapacity)

Constructs a new, empty hashtable with the specified initial capacity and default load factor, which is 0.75.

Parameters:

initialCapacity - the initial capacity of the hashtable.

Throws:

IllegalArgumentException - if the initial capacity is less than zero.

LongHashtable

public LongHashtable(int initialCapacity,
                     float loadFactor)

Constructs a new, empty hashtable with the specified initial capacity and the specified load factor.

Parameters:

initialCapacity - the initial capacity of the hashtable.

loadFactor - the load factor of the hashtable.

Throws:

IllegalArgumentException - if the initial capacity is less than zero, or if the load factor is nonpositive.

Method Detail

size

public int size()

Returns the number of keys in this hashtable.

Returns:

the number of keys in this hashtable.

isEmpty

public boolean isEmpty()

Tests if this hashtable maps no keys to values.

Returns:

true if this hashtable maps no keys to values; false otherwise.

contains

public boolean contains(long value)

Tests if some key maps into the specified value in this hashtable. This operation is more expensive than the containsKey method.

Note that this method is identical in functionality to containsValue, (which is part of the Map interface in the collections framework).

Parameters:

value - a value to search for.

Returns:

true if and only if some key maps to the value argument in this hashtable as determined by the equals method; false otherwise.

Throws:

NullPointerException - if the value is null.

See Also:

#containsKey(int), #containsValue(int), Map

containsValue

public boolean containsValue(long value)

Returns true if this HashMap maps one or more keys to this value.

Note that this method is identical in functionality to contains (which predates the Map interface).

Parameters:

value - value whose presence in this HashMap is to be tested.

Returns:

boolean true if the value is contained

Since:

JDK1.2

See Also:

Map

containsKey

public boolean containsKey(long key)

Tests if the specified int is a key in this hashtable.

Parameters:

key - possible key.

Returns:

true if and only if the specified int is a key in this hashtable, as determined by the equals method; false otherwise.

See Also:

#contains(int)

get

public long get(long key)

Returns the value to which the specified key is mapped in this map.

Parameters:

key - a key in the hashtable.

Returns:

the value to which the key is mapped in this hashtable; null if the key is not mapped to any value in this hashtable.

See Also:

#put(int, int)

rehash

protected void rehash()

Increases the capacity of and internally reorganizes this hashtable, in order to accommodate and access its entries more efficiently.

This method is called automatically when the number of keys in the hashtable exceeds this hashtable's capacity and load factor.

put

public long put(long key,
                long value)

Maps the specified key to the specified value in this hashtable. The key cannot be null.

The value can be retrieved by calling the get method with a key that is equal to the original key.

Parameters:

key - the hashtable key.

value - the value.

Returns:

the previous value of the specified key in this hashtable, or null if it did not have one.

Throws:

NullPointerException - if the key is null.

See Also:

#get(int)

remove

public long remove(long key)

Removes the key (and its corresponding value) from this hashtable.

This method does nothing if the key is not present in the hashtable.

Parameters:

key - the key that needs to be removed.

Returns:

the value to which the key had been mapped in this hashtable, or null if the key did not have a mapping.

clear

public void clear()

Clears this hashtable so that it contains no keys.

getEntryIterator

public Iterator<com.itextpdf.text.pdf.LongHashtable.Entry> getEntryIterator()

toOrderedKeys

public long[] toOrderedKeys()

getKeys

public long[] getKeys()

getOneKey

public long getOneKey()

clone

public Object clone()

Overrides:

clone in class Object