uk.ac.ed.inf.utils.maputils
Class OneToManyMap<T,U>

java.lang.Object
  uk.ac.ed.inf.utils.maputils.OneToManyMap<T,U>

Direct Known Subclasses:

IndexedOneToManyMap

public class OneToManyMap<T,U>
extends java.lang.Object

A map containing for each key a set of values. No key can be null. At most one key can be an empty-string. No value can be null (the Java TreeSet class used uses "null" as a return message when there is *no* mapping for a given key!). A value can be an empty string.

Version:

3 Jun 2008

Author:

Luna De Ferrari luna.deferrari-at-ed.ac.uk

Field Summary

java.util.TreeMap<T,java.util.Set<U>>

m_map the map containing for each key the collection of values that key can have

Constructor Summary

OneToManyMap()
Initialise an empty map

OneToManyMap(java.util.Vector<T> keys, java.util.Vector<U> values)
Initialise with a list of key-value pairs

Method Summary

void	addAll(OneToManyMap<T,U> mapToAdd) Add all elements of a one2many map to another map
boolean	addKeyAndValue(T key, U value) Add a key-value pair to the map
boolean	containsKey(T key) Checks if the map contains a key
boolean	containsKeyValue(T key, U value) Checks if the map contains a specific key-value pair
boolean	containsValue(U value) Checks if the map contains a value
boolean	deleteKeyValue(T key, U value)
java.util.Set<U>	getAKeyValues(T key) Get the set of unique values for this key.
java.util.Set<T>	getKeys()
java.util.Vector<java.util.Vector>	getKeysVectorValuesVector() Get 1.
int	getKeyValuesPairsSize() Get the number of unique key-value pairs in the map.
java.util.TreeMap<T,java.util.Set<U>>	getMap()
java.util.Set<T>	getNonEmptyKeys() Get the set of unique, non-empty-string keys for this map.
int	getNonEmptyKeyValuesPairsSize() Get the number of unique, non-empty key-value pairs in the map.
java.util.Set<U>	getNonEmptyValues() Get the set of unique, non-empty-string values for this map.
java.util.Set<U>	getValues() Get the set of unique values for this map.
void	initialise()
boolean	mapIsNullOrEmpty() public void initialise(Vector keys, Vector values) { this.setMap(); this.generateMap(keys, values); }
int	size()
java.lang.String	toCSV() Get a list of comma separated [key, value] couples.
java.lang.String	toString()

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

m_map

public java.util.TreeMap<T,java.util.Set<U>> m_map

the map containing for each key the collection of values that key can have

Constructor Detail

OneToManyMap

public OneToManyMap()

Initialise an empty map

OneToManyMap

public OneToManyMap(java.util.Vector<T> keys,
                    java.util.Vector<U> values)

Initialise with a list of key-value pairs

Parameters:

keys - the list of keys

values - the list of values (the value for each key in the keys list)

Method Detail

addAll

public void addAll(OneToManyMap<T,U> mapToAdd)

Add all elements of a one2many map to another map

Parameters:

map - the map whose elements have to be added

addKeyAndValue

public boolean addKeyAndValue(T key,
                              U value)

Add a key-value pair to the map

Parameters:

key - a key

value - a value

Returns:

true if the value was added, false if the key-value pair already existed

containsKey

public boolean containsKey(T key)

Checks if the map contains a key

Parameters:

key -

Returns:

true if the key exists in the map, false otherwise

containsKeyValue

public boolean containsKeyValue(T key,
                                U value)

Checks if the map contains a specific key-value pair

Parameters:

key -

value -

Returns:

true if the key-value exists, false otherwise (false if the key or value are null)

containsValue

public boolean containsValue(U value)

Checks if the map contains a value

Parameters:

value - a value

Returns:

true if the value exists in the map, false otherwise

deleteKeyValue

public boolean deleteKeyValue(T key,
                              U value)

getAKeyValues

public java.util.Set<U> getAKeyValues(T key)

Get the set of unique values for this key. No values can be null. At most one of the values can be an empty string.

Returns:

the set of unique values for this key

getKeys

public java.util.Set<T> getKeys()

getKeysVectorValuesVector

public java.util.Vector<java.util.Vector> getKeysVectorValuesVector()

Get 1. a first vector containing each key as many times as values exist for the key. 2. a second vector containing one corresponding value for each key entry in the first vector. The two vectors together create a 2 vectors representation of the map (key in vector 1, value in vector 2). Example, for a map: [1:{a, b}, 2:{b, c}] the keys vector will contain: [1, 1, 2, 2]. While the values vector will contain: [a, b, b, c]. Read together, element by element, they give the map couples.

Returns:

a vector of vectors, with the first vector being the keys vector and the second being the values vector.

getKeyValuesPairsSize

public int getKeyValuesPairsSize()

Get the number of unique key-value pairs in the map. No key can be null. At most one of the keys can be an empty string. The values can be empty strings.

Returns:

the number of unique key-value pairs in the map

getMap

public java.util.TreeMap<T,java.util.Set<U>> getMap()

getNonEmptyKeys

public java.util.Set<T> getNonEmptyKeys()

Get the set of unique, non-empty-string keys for this map.

Returns:

the set of unique, non-empty-string keys for this map

getNonEmptyKeyValuesPairsSize

public int getNonEmptyKeyValuesPairsSize()

Get the number of unique, non-empty key-value pairs in the map. No key can be null. Empty string keys will not be included, nor will empty string values.

Returns:

the number of unique key-value pairs in the map

getNonEmptyValues

public java.util.Set<U> getNonEmptyValues()

Get the set of unique, non-empty-string values for this map.

Returns:

the set of unique, non-empty-string values for this map

getValues

public java.util.Set<U> getValues()

Get the set of unique values for this map. At most one value can be null. At most one value can be an empty string.

Returns:

the set of unique values for this map

initialise

public void initialise()

mapIsNullOrEmpty

public boolean mapIsNullOrEmpty()

public void initialise(Vector keys, Vector values) { this.setMap(); this.generateMap(keys, values); }

size

public int size()

toCSV

public java.lang.String toCSV()

Get a list of comma separated [key, value] couples.

Returns:

a list of comma separated [key, value] couples.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object