org.owasp.esapi.codecs
Class HashTrie<T>

java.lang.Object
  org.owasp.esapi.codecs.HashTrie<T>

All Implemented Interfaces:

java.util.Map<java.lang.CharSequence,T>, Trie<T>

public class HashTrie<T>
extends java.lang.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:

• Map.remove(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.esapi.codecs.Trie

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

Constructor Summary

HashTrie()

Method Summary

void	clear() Clear all entries.
boolean	containsKey(java.lang.Object key)
boolean	containsValue(java.lang.Object value)
java.util.Set<java.util.Map.Entry<java.lang.CharSequence,T>>	entrySet()
boolean	equals(java.lang.Object other)
T	get(java.lang.Object key) Get the value for a key.
java.util.Map.Entry<java.lang.CharSequence,T>	getLongestMatch(java.lang.CharSequence key) Get the key value entry who's key is the longest prefix match.
java.util.Map.Entry<java.lang.CharSequence,T>	getLongestMatch(java.io.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()
java.util.Set<java.lang.CharSequence>	keySet()
T	put(java.lang.CharSequence key, T value) Add mapping.
void	putAll(java.util.Map<? extends java.lang.CharSequence,? extends T> map)
T	remove(java.lang.Object key) Remove a entry.
int	size() Get the number of entries.
java.lang.String	toString()
java.util.Collection<T>	values()

Methods inherited from class java.lang.Object

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

Constructor Detail

HashTrie

public HashTrie()

Method Detail

getLongestMatch

public java.util.Map.Entry<java.lang.CharSequence,T> getLongestMatch(java.lang.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 java.util.Map.Entry<java.lang.CharSequence,T> getLongestMatch(java.io.PushbackReader keyIn)
                                                              throws java.io.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:

java.io.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 java.util.Map<java.lang.CharSequence,T>

containsKey

public boolean containsKey(java.lang.Object key)

Specified by:

containsKey in interface java.util.Map<java.lang.CharSequence,T>

containsValue

public boolean containsValue(java.lang.Object value)

Specified by:

containsValue in interface java.util.Map<java.lang.CharSequence,T>

put

public T put(java.lang.CharSequence key,
             T value)
      throws java.lang.NullPointerException

Add mapping.

Specified by:

put in interface java.util.Map<java.lang.CharSequence,T>

Parameters:

key - The mapping's key.

Throws:

java.lang.NullPointerException - if key or value is null.

remove

public T remove(java.lang.Object key)
         throws java.lang.UnsupportedOperationException

Remove a entry.

Specified by:

remove in interface java.util.Map<java.lang.CharSequence,T>

Returns:

previous value

Throws:

java.lang.UnsupportedOperationException - always.

putAll

public void putAll(java.util.Map<? extends java.lang.CharSequence,? extends T> map)

Specified by:

putAll in interface java.util.Map<java.lang.CharSequence,T>

keySet

public java.util.Set<java.lang.CharSequence> keySet()

Specified by:

keySet in interface java.util.Map<java.lang.CharSequence,T>

values

public java.util.Collection<T> values()

Specified by:

values in interface java.util.Map<java.lang.CharSequence,T>

entrySet

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

Specified by:

entrySet in interface java.util.Map<java.lang.CharSequence,T>

get

public T get(java.lang.Object key)

Get the value for a key.

Specified by:

get in interface java.util.Map<java.lang.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 java.util.Map<java.lang.CharSequence,T>

Returns:

the number or entries.

equals

public boolean equals(java.lang.Object other)

Specified by:

equals in interface java.util.Map<java.lang.CharSequence,T>

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Specified by:

hashCode in interface java.util.Map<java.lang.CharSequence,T>

Overrides:

hashCode in class java.lang.Object

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface java.util.Map<java.lang.CharSequence,T>