java.lang.Object
com.sun.xml.dtdparser.SimpleHashtable<K,V>
- All Implemented Interfaces:
Enumeration<K>
This class implements a special purpose hashtable. It works like a
normal
java.util.Hashtable except that: - Keys to "get" are strings which are known to be interned, so that "==" is used instead of "String.equals". (Interning could be document-relative instead of global.)
- It's not synchronized, since it's to be used only by one thread at a time.
- The keys () enumerator allocates no memory, with live updates to the data disallowed.
- It's got fewer bells and whistles: fixed threshold and load factor, no JDK 1.2 collection support, only keys can be enumerated, things can't be removed, simpler inheritance; more.
The overall result is that it's less expensive to use these in
performance-critical locations, in terms both of CPU and memory,
than java.util.Hashtable instances. In this package
it makes a significant difference when normalizing attributes,
which is done for each start-element construct.
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Nested Class Summary
Nested ClassesModifier and TypeClassDescriptionprivate static classHashtable collision list. -
Field Summary
FieldsModifier and TypeFieldDescriptionprivate intprivate SimpleHashtable.Entry<K, V> private intprivate static final floatprivate SimpleHashtable.Entry<K,V>[] private int -
Constructor Summary
ConstructorsConstructorDescriptionConstructs a new, empty hashtable with a default capacity.SimpleHashtable(int initialCapacity) Constructs a new, empty hashtable with the specified initial capacity. -
Method Summary
Modifier and TypeMethodDescriptionvoidclear()Returns the value to which the specified key is mapped in this hashtable.getNonInterned(String key) Returns the value to which the specified key is mapped in this hashtable ...booleanUsed to view this as an enumeration; returns true if there are more keys to be enumerated.keys()Returns an enumeration of the keys in this hashtable.Used to view this as an enumeration; returns the next key in the enumeration.Maps the specifiedkeyto the specifiedvaluein this hashtable.private voidrehash()Increases the capacity of and internally reorganizes this hashtable, in order to accommodate and access its entries more efficiently.intsize()Returns the number of keys in this hashtable.Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, waitMethods inherited from interface java.util.Enumeration
asIterator
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Field Details
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table
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current
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currentBucket
private int currentBucket -
count
private int count -
threshold
private int threshold -
loadFactor
private static final float loadFactor- See Also:
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Constructor Details
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SimpleHashtable
public SimpleHashtable(int initialCapacity) Constructs a new, empty hashtable with the specified initial capacity.- Parameters:
initialCapacity- the initial capacity of the hashtable.
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SimpleHashtable
public SimpleHashtable()Constructs a new, empty hashtable with a default capacity.
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Method Details
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clear
public void clear() -
size
public int size()Returns the number of keys in this hashtable.- Returns:
- the number of keys in this hashtable.
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keys
Returns an enumeration of the keys in this hashtable.- Returns:
- an enumeration of the keys in this hashtable.
- See Also:
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hasMoreElements
public boolean hasMoreElements()Used to view this as an enumeration; returns true if there are more keys to be enumerated.- Specified by:
hasMoreElementsin interfaceEnumeration<K>
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nextElement
Used to view this as an enumeration; returns the next key in the enumeration.- Specified by:
nextElementin interfaceEnumeration<K>
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get
Returns the value to which the specified key is mapped in this hashtable. -
getNonInterned
Returns the value to which the specified key is mapped in this hashtable ... the key isn't necessarily interned, though. -
rehash
private 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 capacity and load factor. -
put
Maps the specifiedkeyto the specifiedvaluein this hashtable. Neither the key nor the value can benull.The value can be retrieved by calling the
getmethod with a key that is equal to the original key.
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