Package megamek.common.util

Class CollectionUtil

java.lang.Object

megamek.common.util.CollectionUtil

public final class CollectionUtil
extends Object

Some utility methods for Collections.

Method Summary

Modifier and Type	Method	Description
static <T> T	anyOneElement(Collection<T> collection)
static <T> Counter<T>	counter(List<T> listOfElements)	\ Returns a hashmap that has the number of occurrence of each element on the list
static <T> T	theElement(Collection<T> collection)	Returns the only element of the collection.
static <T> List<T>	union(List<T> c1, List<T> c2)	Returns a list that is the concatenation of the provided lists.

Methods inherited from class java.lang.Object

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

Method Details

union

public static <T> List<T> union(List<T> c1,
 List<T> c2)

Returns a list that is the concatenation of the provided lists. Does NOT do anything else (e.g. remove duplicate entries).

counter

public static <T> Counter<T> counter(List<T> listOfElements)

\ Returns a hashmap that has the number of occurrence of each element on the list

Parameters:

listOfElements - List of elements to count.

Returns:

Map with the count of each element in the list.

anyOneElement

public static <T> T anyOneElement(Collection<T> collection)

Returns:

One element (not randomly chosen) of the collection or the element if it has only one.

Throws:

NoSuchElementException - if the collection is empty.

theElement

public static <T> T theElement(Collection<T> collection)

Returns the only element of the collection. Throws an IllegalArgument exception if the collection size is greater than 1. Throws a NoSuchElement exception if it is empty.