uk.ac.ed.inf.utils.maputils
Class MapUtils

java.lang.Object
  uk.ac.ed.inf.utils.maputils.MapUtils

public class MapUtils
extends java.lang.Object

Utilities to manipulate maps and hashmaps

Version:

4 Jan 2008

Author:

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

Constructor Summary

MapUtils()

Method Summary

static java.util.Map.Entry	extractMapEntry(java.util.Map map, int i) Extracts a random entry (key-value association) from a map
static java.util.TreeMap<java.lang.String,java.lang.String>	fromTwoVectorsToMap(java.util.Vector<java.lang.String> keys, java.util.Vector<java.lang.String> values) Creates an hashmap from 2 vectors.
static double	getDoubleFromHashmap(java.util.HashMap hashMap, java.lang.String hashMapKey) Gets a double from a hashMap
static java.util.ArrayList<java.lang.String>	getFirstValueOccurrence(java.util.Map<java.lang.String,java.lang.String> map, java.lang.String value) Get all the keys that have the given value in a Map\
static java.util.Map<java.lang.Integer,java.util.Map.Entry>	getIndexedMap(java.lang.Object[] mapEntries) Get a map with entries composed of: an integer id as key and an entry as value
static java.lang.String	mapToString(java.util.Map map) Creates a string representation of a map, as index,tab,key,tab,value
static void	printMap(java.util.Map map) Prints an HashMap as a list of index + key + value
static boolean	treeMapsHaveEqualValues(java.util.TreeMap<java.lang.Integer,java.lang.Character> map1, java.util.TreeMap<java.lang.Integer,java.lang.Character> map2) Check if two treeMaps have the same collection of values

Methods inherited from class java.lang.Object

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

Constructor Detail

MapUtils

public MapUtils()

Method Detail

extractMapEntry

public static java.util.Map.Entry extractMapEntry(java.util.Map map,
                                                  int i)

Extracts a random entry (key-value association) from a map

Parameters:

map - a map

Returns:

a random (truncated Pareto distributed) entry from the map

fromTwoVectorsToMap

public static java.util.TreeMap<java.lang.String,java.lang.String> fromTwoVectorsToMap(java.util.Vector<java.lang.String> keys,
                                                                                       java.util.Vector<java.lang.String> values)

Creates an hashmap from 2 vectors. The first vector must contain a the keys, the second vector the values. The keys and values vectors must have the same size.

Parameters:

keys -

values -

Returns:

an HashMap

getDoubleFromHashmap

public static double getDoubleFromHashmap(java.util.HashMap hashMap,
                                          java.lang.String hashMapKey)

Gets a double from a hashMap

getFirstValueOccurrence

public static java.util.ArrayList<java.lang.String> getFirstValueOccurrence(java.util.Map<java.lang.String,java.lang.String> map,
                                                                            java.lang.String value)

Get all the keys that have the given value in a Map\

Parameters:

map - a map

value - a hash map value

Returns:

the keys

getIndexedMap

public static java.util.Map<java.lang.Integer,java.util.Map.Entry> getIndexedMap(java.lang.Object[] mapEntries)

Get a map with entries composed of: an integer id as key and an entry as value

Parameters:

mapEntries - an array of Entry objects

Returns:

a map with entries composed of: an integer id as key and an entry as value

mapToString

public static java.lang.String mapToString(java.util.Map map)

Creates a string representation of a map, as index,tab,key,tab,value

Returns:

a string representation of the map

printMap

public static void printMap(java.util.Map map)

Prints an HashMap as a list of index + key + value

Parameters:

map -

treeMapsHaveEqualValues

public static boolean treeMapsHaveEqualValues(java.util.TreeMap<java.lang.Integer,java.lang.Character> map1,
                                              java.util.TreeMap<java.lang.Integer,java.lang.Character> map2)

Check if two treeMaps have the same collection of values

Parameters:

map1 -

map2 -

Returns:

true, if the two treeMaps have the same collection of values