Class LongHashtable
- java.lang.Object
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- com.itextpdf.text.pdf.LongHashtable
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- All Implemented Interfaces:
java.lang.Cloneable
public class LongHashtable extends java.lang.Object implements java.lang.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)
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Constructor Summary
Constructors Constructor Description LongHashtable()
Constructs a new, empty hashtable with a default capacity and load factor, which is20
and0.75
respectively.LongHashtable(int initialCapacity)
Constructs a new, empty hashtable with the specified initial capacity and default load factor, which is0.75
.LongHashtable(int initialCapacity, float loadFactor)
Constructs a new, empty hashtable with the specified initial capacity and the specified load factor.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
clear()
Clears this hashtable so that it contains no keys.java.lang.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)
Returnstrue
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.java.util.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 specifiedkey
to the specifiedvalue
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()
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Constructor Detail
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LongHashtable
public LongHashtable()
Constructs a new, empty hashtable with a default capacity and load factor, which is
20
and0.75
respectively.
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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:
java.lang.IllegalArgumentException
- if the initial capacity is less than zero.
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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:
java.lang.IllegalArgumentException
- if the initial capacity is less than zero, or if the load factor is nonpositive.
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Method Detail
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size
public int size()
Returns the number of keys in this hashtable.
- Returns:
- the number of keys in this hashtable.
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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.
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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 thevalue
argument in this hashtable as determined by the equals method;false
otherwise.- Throws:
java.lang.NullPointerException
- if the value isnull
.- See Also:
#containsKey(int)
,#containsValue(int)
,Map
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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
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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)
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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)
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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.
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put
public long put(long key, long value)
Maps the specified
key
to the specifiedvalue
in this hashtable. The key cannot benull
.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:
java.lang.NullPointerException
- if the key isnull
.- See Also:
#get(int)
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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.
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clear
public void clear()
Clears this hashtable so that it contains no keys.
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getEntryIterator
public java.util.Iterator<com.itextpdf.text.pdf.LongHashtable.Entry> getEntryIterator()
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toOrderedKeys
public long[] toOrderedKeys()
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getKeys
public long[] getKeys()
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getOneKey
public long getOneKey()
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clone
public java.lang.Object clone()
- Overrides:
clone
in classjava.lang.Object
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