org.abstracthorizon.danube.http.util
Class MultiStringHashMap

java.lang.Object
  org.abstracthorizon.danube.http.util.MultiStringHashMap

All Implemented Interfaces:

MultiStringMap

public class MultiStringHashMap
extends Object
implements MultiStringMap

MultiStringMap implementation using HashMap This implementation uses map and is storing multiple elements in a list. If only one element remains in the list then it is replaced with that element only.

Author:

Daniel Sendula

Nested Class Summary

protected class

MultiStringHashMap.InternalMapEntry<K,V> Map entry for internal use

Field Summary

protected Map<String,Object>

map Backing storage.

Constructor Summary

MultiStringHashMap()
Constructor.

MultiStringHashMap(int initialCapacity)
Constructor.

MultiStringHashMap(int initialCapacity, float loadFactor)
Constructor.

Method Summary

void	add(String id, String value) Adds new element to the map.
void	addAll(String id, Collection<String> values) Adds all elements from the given collection
void	addAll(String id, String[] values) Adds all elements from the given array.
void	clear() Clears the map
boolean	containsKey(String id) Returns true if there is at least one entry
Collection<Map.Entry<String,String>>	getAllEntries() Returns list of all entries.
String[]	getAsArray(String id) Returns array of all elements under asked key.
List<String>	getAsList(String id) Returns list of all elements under asked key.
Map<String,Object>	getAsMap() Returns a map that contains all elements.
int	getEntrySize(String id) Returns number of entries for given key
String	getFirst(String id) Retrieves element from the given key.
String	getOnly(String id) Retrieves element from the given key.
Set<String>	keySet() Returns key set
void	putAll(String id, Collection<String> values) Replaces existing element(s), if there are any under the given key, with the given values.
void	putAll(String id, String[] values) Replaces existing element(s), if there are any under the given key, with the given values.
void	putOnly(String id, String value) Replaces existing element(s), if there are any under the given key, with the given value.
String	remove(String id, int index) Removes n-th element from the given key.
Collection<String>	removeAll(String id) Removes all elements from the given key
String	removeFirst(String id) Removes first element from the given key.
int	size() Number of keys in the map.

Methods inherited from class java.lang.Object

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

Field Detail

map

protected Map<String,Object> map

Backing storage.

Constructor Detail

MultiStringHashMap

public MultiStringHashMap()

Constructor.

MultiStringHashMap

public MultiStringHashMap(int initialCapacity)

Constructor.

Parameters:

initialCapacity - initial capacity of a backing map

MultiStringHashMap

public MultiStringHashMap(int initialCapacity,
                          float loadFactor)

Constructor.

Parameters:

initialCapacity - initial capacity of a backing map

loadFactor - load factory of a backing map

Method Detail

add

public void add(String id,
                String value)

Adds new element to the map. If no entries with given id exist than this is going to be the first. If there are already values under given id then this is going to be added as a new one.

This implementation if there is already one value in the backing map converts it to a list and adds both (old and new values) to it.

Specified by:

add in interface MultiStringMap

Parameters:

id - key

value - value to be added

Throws:

IllegalStateException - if existing element of the backing storage is not a string or a list

addAll

public void addAll(String id,
                   String[] values)

Adds all elements from the given array.

This implementation is using addAll(String, Collection) to add values

Specified by:

addAll in interface MultiStringMap

Parameters:

id - key

values - array of values

See Also:

MultiStringMap.add(String, String)

addAll

public void addAll(String id,
                   Collection<String> values)

Adds all elements from the given collection

This implementation if there is already one value in the backing map converts it to a list and adds both (old and new values) to it.

Specified by:

addAll in interface MultiStringMap

Parameters:

id - key

values - collection which elements are to be added

Throws:

IllegalStateException - if existing element of the backing storage is not a string or a list

See Also:

MultiStringMap.add(String, String)

putOnly

public void putOnly(String id,
                    String value)

Replaces existing element(s), if there are any under the given key, with the given value.

Specified by:

putOnly in interface MultiStringMap

Parameters:

id - key

value - value to be put to the map

putAll

public void putAll(String id,
                   String[] values)

Replaces existing element(s), if there are any under the given key, with the given values.

If array's length is greater then one it stores given array of strings as a list, if arrayls. If array's length is exactly one then value of it is stored as a string while if array's length is zero then it is removed from the backing storage.

Specified by:

putAll in interface MultiStringMap

Parameters:

id - key

values - values to be put to the map

See Also:

MultiStringMap.putOnly(String, String)

putAll

public void putAll(String id,
                   Collection<String> values)

Replaces existing element(s), if there are any under the given key, with the given values.

If array's length is greater then one it stores given array of strings as a list, if arrayls. If array's length is exactly one then value of it is stored as a string while if array's length is zero then it is removed from the backing storage.

Note: This implementation is not ensuring that all collection elements are of String type.

Specified by:

putAll in interface MultiStringMap

Parameters:

id - key

values - collection of values to be put to the map

See Also:

MultiStringMap.putOnly(String, String)

removeAll

public Collection<String> removeAll(String id)

Removes all elements from the given key

Specified by:

removeAll in interface MultiStringMap

Parameters:

id - key

removeFirst

public String removeFirst(String id)

Removes first element from the given key. If there was only one element then there will be no more elements under the given key

Implementation ensures that if list is reduced to only one element then that element is stored instead of the list itself.

Specified by:

removeFirst in interface MultiStringMap

Parameters:

id - key

Throws:

IllegalStateException - if the element of the backing storage is not string nor list or there are no elements to be removed

remove

public String remove(String id,
                     int index)

Removes n-th element from the given key.

Implementation ensures that if list is reduced to only one element then that element is stored instead of the list itself.

Specified by:

remove in interface MultiStringMap

Parameters:

id - key

index - index of the element to be removed

Throws:

IndexOutOfBoundsException - if there are no elements under the given key

IllegalStateException - if the element of the backing storage is not string nor list or there are no elements to be removed

containsKey

public boolean containsKey(String id)

Returns true if there is at least one entry

Specified by:

containsKey in interface MultiStringMap

Parameters:

id - key

Returns:

true if there is at least one entry

getEntrySize

public int getEntrySize(String id)

Returns number of entries for given key

Specified by:

getEntrySize in interface MultiStringMap

Parameters:

id - key

Returns:

number of entries for given key

getOnly

public String getOnly(String id)

Retrieves element from the given key. Key must have only one element (or none) for this method to work.

Specified by:

getOnly in interface MultiStringMap

Parameters:

id - key of the asked element

Returns:

element

Throws:

IllegalStateException - if there are more then one element under this key or nor string or list is stored in the backing storage

getFirst

public String getFirst(String id)

Retrieves element from the given key. Key must have only one element (or none) for this method to work.

Specified by:

getFirst in interface MultiStringMap

Parameters:

id - key of the asked element

Returns:

element

Throws:

IllegalStateException - if there are more then one element under this key or nor string or list is stored in the backing storage

getAsArray

public String[] getAsArray(String id)

Returns array of all elements under asked key. If there are no elements then it returns an empty array.

Specified by:

getAsArray in interface MultiStringMap

Parameters:

id - key of the asked elements

Returns:

an array of strings

Throws:

IllegalStateException - if the element of the backing storage is not string nor list or there are no elements to be removed

getAsList

public List<String> getAsList(String id)

Returns list of all elements under asked key. If there are no elements then it returns an empty list.

Specified by:

getAsList in interface MultiStringMap

Parameters:

id - key of the asked elements

Returns:

a list of strings

Throws:

IllegalStateException - if the element of the backing storage is not string nor list or there are no elements to be removed

clear

public void clear()

Clears the map

Specified by:

clear in interface MultiStringMap

keySet

public Set<String> keySet()

Returns key set

Specified by:

keySet in interface MultiStringMap

Returns:

key set

getAsMap

public Map<String,Object> getAsMap()

Returns a map that contains all elements. Where there are more elements per key then implementation is responsiple of returning something sensible like an array of strings or a collection (or a list) whose elements are strings

Specified by:

getAsMap in interface MultiStringMap

Returns:

a map

getAllEntries

public Collection<Map.Entry<String,String>> getAllEntries()

Returns list of all entries. Entries with the same key will repeat if there are more elements stored under the same key.

Specified by:

getAllEntries in interface MultiStringMap

Returns:

list of all entries

Throws:

IllegalStateException - if the element of the backing storage is not string nor list or there are no elements to be removed

size

public int size()

Number of keys in the map. It won't return total number of elements but just number of differnet keys in the map.

Specified by:

size in interface MultiStringMap

Returns:

number of keys in the map