arlut.csd.Util

Class VectorUtils

java.lang.Object

arlut.csd.Util.VectorUtils

public class VectorUtils
extends java.lang.Object

Convenience methods for working with Vectors.. provides efficient Union, Intersection, and Difference methods.

Constructor Summary

Constructors

Constructor and Description
VectorUtils()

Method Summary

Methods

Modifier and Type	Method and Description
static <E> java.util.Vector<E>	difference(java.util.List<E> vectA, java.util.List<E> vectB) This method returns a Vector containing the set of objects contained in vectA that are not contained in vectB.
static <E> java.util.Vector<E>	duplicates(java.util.List<E> vector) This method returns a Vector of items that appeared in the vector parameter more than once.
static <E> boolean	equalMembers(java.util.List<E> vectA, java.util.List<E> vectB) This method returns true if vectA and vectB contain the same elements, in whatever order.
private static int	findNextSep(java.lang.String input, int startDex, java.lang.String sepChars) findNextSep() takes a string, a starting position, and a string of characters to be considered field separators, and returns the first index after startDex whose char is in sepChars.
static <E> java.util.Vector<E>	intersection(java.util.List<E> vectA, java.util.List<E> vectB) This method returns a Vector containing the intersection of the objects contained in vectA and vectB.
static void	main(java.lang.String[] args)
static <E> java.util.Vector<E>	minus(java.util.List<E> vectA, java.util.List<E> vectB) This method returns a Vector containing the elements of vectA minus the elements of vectB.
static <E> boolean	overlaps(java.util.List<E> vectA, java.util.List<E> vectB) Returns true if vectA and vectB have any elements in common.
static java.util.Vector	stringVector(java.lang.String input, java.lang.String sepChars) This method takes a sepChars-separated string and converts it to a vector of fields.
static <E> java.util.Vector<E>	union(java.util.List<E> vectA, java.util.List<E> vectB) This method returns a Vector containing the union of the objects contained in vectA and vectB.
static <E> void	unionAdd(java.util.List<E> vect, E obj) This method adds obj to vect if and only if vect does not already contain obj.
static java.lang.String	vectorString(java.util.Collection vec) This method returns a string containing all the elements in vec concatenated together, comma separated.
static java.lang.String	vectorString(java.util.Collection vec, java.lang.String separator) This method returns a string containing all the elements in vec concatenated together, comma separated.
private static int	vectSize(java.util.List x)

Methods inherited from class java.lang.Object

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

Constructor Detail

VectorUtils

public VectorUtils()

Method Detail

union

public static <E> java.util.Vector<E> union(java.util.List<E> vectA,
                            java.util.List<E> vectB)

This method returns a Vector containing the union of the objects contained in vectA and vectB. The resulting Vector will not contain any duplicates, even if vectA or vectB themselves contain repeated items.

This method will always return a new, non-null Vector, even if vectA and/or vectB are null.

unionAdd

public static <E> void unionAdd(java.util.List<E> vect,
                E obj)

This method adds obj to vect if and only if vect does not already contain obj.

overlaps

public static <E> boolean overlaps(java.util.List<E> vectA,
                   java.util.List<E> vectB)

Returns true if vectA and vectB have any elements in common.

intersection

public static <E> java.util.Vector<E> intersection(java.util.List<E> vectA,
                                   java.util.List<E> vectB)

This method returns a Vector containing the intersection of the objects contained in vectA and vectB.

This method will always return a new, non-null Vector, even if vectA and/or vectB are null.

difference

public static <E> java.util.Vector<E> difference(java.util.List<E> vectA,
                                 java.util.List<E> vectB)

This method returns a Vector containing the set of objects contained in vectA that are not contained in vectB.

NB: This method differs from minus(), which explicitly handles lists with duplicate members and returns an algebraic count of the non-duplicates. By contrast, difference() returns a Vector with no duplicates.

This method will always return a new, non-null Vector, even if vectA and/or vectB are null.

equalMembers

public static <E> boolean equalMembers(java.util.List<E> vectA,
                       java.util.List<E> vectB)

This method returns true if vectA and vectB contain the same elements, in whatever order.

duplicates

public static <E> java.util.Vector<E> duplicates(java.util.List<E> vector)

This method returns a Vector of items that appeared in the vector parameter more than once.

If no duplicates are found or if vector is null, this method returns null.

minus

public static <E> java.util.Vector<E> minus(java.util.List<E> vectA,
                            java.util.List<E> vectB)

This method returns a Vector containing the elements of vectA minus the elements of vectB.

NB: This method is not a synonym for difference(). With minus(), if vectA has an element in the Vector 5 times and vectB has it 3 times, the result will have it two times. difference() always returns a Vector without duplicates

This method will always return a new, non-null Vector, even if vectA and/or vectB are null.

vectorString

public static java.lang.String vectorString(java.util.Collection vec)

This method returns a string containing all the elements in vec concatenated together, comma separated.

vectorString

public static java.lang.String vectorString(java.util.Collection vec,
                            java.lang.String separator)

This method returns a string containing all the elements in vec concatenated together, comma separated.

stringVector

public static java.util.Vector stringVector(java.lang.String input,
                            java.lang.String sepChars)

This method takes a sepChars-separated string and converts it to a vector of fields. i.e., "gomod,jonabbey" -> a vector whose elements are "gomod" and "jonabbey".

NOTE: this method will omit 'degenerate' fields from the output vector. That is, if input is "gomod,,, jonabbey" and sepChars is ", ", then the result vector will still only have "gomod" and "jonabbey" as elements, even though one might wish to explicitly know about the blanks between commas. This method is intended mostly for creating email list vectors, rather than general file-parsing vectors.

Parameters:

input - the sepChars-separated string to test.

sepChars - a string containing a list of characters which may occur as field separators. Any two fields in the input may be separated by one or many of the characters present in sepChars.

findNextSep

private static int findNextSep(java.lang.String input,
              int startDex,
              java.lang.String sepChars)

findNextSep() takes a string, a starting position, and a string of characters to be considered field separators, and returns the first index after startDex whose char is in sepChars.

If there are no chars in sepChars past startdex in input, findNextSep() returns -1.

vectSize

private static int vectSize(java.util.List x)

main

public static void main(java.lang.String[] args)