org.owasp.fileio.codecs

Class HashTrie<T>

java.lang.Object

org.owasp.fileio.codecs.HashTrie<T>

All Implemented Interfaces:

Map<CharSequence,T>, Trie<T>

public class HashTrie<T>
extends Object
implements Trie<T>

Trie implementation for CharSequence keys. This uses HashMaps for each level instead of the traditional array. This is done as with unicode, each level's array would be 64k entries. NOTE:

• java.util.Map.remove(java.lang.Object) is not supported.
• If deletion support is added the max key length will need work or removal.
• Null values are not supported.

Author:

Ed Schaller

Nested Class Summary

Nested classes/interfaces inherited from interface org.owasp.fileio.codecs.Trie

Trie.TrieProxy<T>, Trie.Unmodifiable<T>, Trie.Util

Constructor Summary

Constructors

Constructor and Description
HashTrie()

Method Summary

Modifier and Type	Method and Description
void	clear() Clear all entries.
boolean	containsKey(Object key)
boolean	containsValue(Object value)
Set<Map.Entry<CharSequence,T>>	entrySet()
boolean	equals(Object other)
T	get(Object key) Get the value for a key.
Map.Entry<CharSequence,T>	getLongestMatch(CharSequence key) Get the key value entry who's key is the longest prefix match.
Map.Entry<CharSequence,T>	getLongestMatch(PushbackReader keyIn) Get the key value entry who's key is the longest prefix match.
int	getMaxKeyLength() Get the maximum key length.
int	hashCode()
boolean	isEmpty()
Set<CharSequence>	keySet()
T	put(CharSequence key, T value) Add mapping.
void	putAll(Map<? extends CharSequence,? extends T> map)
T	remove(Object key) Remove a entry.
int	size() Get the number of entries.
String	toString()
Collection<T>	values()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Map

compute, computeIfAbsent, computeIfPresent, forEach, getOrDefault, merge, putIfAbsent, remove, replace, replace, replaceAll

Constructor Detail

HashTrie

public HashTrie()

Method Detail

getLongestMatch

public Map.Entry<CharSequence,T> getLongestMatch(CharSequence key)

Get the key value entry who's key is the longest prefix match.

Specified by:

getLongestMatch in interface Trie<T>

Parameters:

key - The key to lookup

Returns:

Entry with the longest matching key.

getLongestMatch

public Map.Entry<CharSequence,T> getLongestMatch(PushbackReader keyIn)
                                          throws IOException

Get the key value entry who's key is the longest prefix match.

Specified by:

getLongestMatch in interface Trie<T>

Parameters:

keyIn - Pushback reader to read the key from. This should have a buffer at least as large as getMaxKeyLength() or an IOException may be thrown backing up.

Returns:

Entry with the longest matching key.

Throws:

IOException - if keyIn.read() or keyIn.unread() does.

getMaxKeyLength

public int getMaxKeyLength()

Get the maximum key length.

Specified by:

getMaxKeyLength in interface Trie<T>

Returns:

max key length.

clear

public void clear()

Clear all entries.

Specified by:

clear in interface Map<CharSequence,T>

containsKey

public boolean containsKey(Object key)

Specified by:

containsKey in interface Map<CharSequence,T>

containsValue

public boolean containsValue(Object value)

Specified by:

containsValue in interface Map<CharSequence,T>

put

public T put(CharSequence key,
             T value)
      throws NullPointerException

Add mapping.

Specified by:

put in interface Map<CharSequence,T>

Parameters:

key - The mapping's key.

value - value The mapping's value

Throws:

NullPointerException - if key or value is null.

remove

public T remove(Object key)
         throws UnsupportedOperationException

Remove a entry.

Specified by:

remove in interface Map<CharSequence,T>

Returns:

previous value

Throws:

UnsupportedOperationException - always.

putAll

public void putAll(Map<? extends CharSequence,? extends T> map)

Specified by:

putAll in interface Map<CharSequence,T>

keySet

public Set<CharSequence> keySet()

Specified by:

keySet in interface Map<CharSequence,T>

values

public Collection<T> values()

Specified by:

values in interface Map<CharSequence,T>

entrySet

public Set<Map.Entry<CharSequence,T>> entrySet()

Specified by:

entrySet in interface Map<CharSequence,T>

get

public T get(Object key)

Get the value for a key.

Specified by:

get in interface Map<CharSequence,T>

Parameters:

key - The key to look up.

Returns:

The value for key or null if the key is not found.

size

public int size()

Get the number of entries.

Specified by:

size in interface Map<CharSequence,T>

Returns:

the number or entries.

equals

public boolean equals(Object other)

Specified by:

equals in interface Map<CharSequence,T>

Overrides:

equals in class Object

hashCode

public int hashCode()

Specified by:

hashCode in interface Map<CharSequence,T>

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface Map<CharSequence,T>