Java Collection Random Element getRandomNumber(Collection collection, int number)

Description

Returns at random a specific number of elements from a collection.

License

Open Source License

Parameter

Parameter	Description
collection	the collection
number	the number of elements

Return

the random elements

Declaration

public static <T> Set<T> getRandomNumber(Collection<T> collection, int number) 

Method Source Code

//package com.java2s;
//License from project: Open Source License 

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

public class Main {
    /**/*from   www.ja  va2 s  . co  m*/
     * Returns at random a specific number of elements from a collection.
     * @param collection the collection
     * @param number the number of elements
     * @return the random elements
     */
    public static <T> Set<T> getRandomNumber(Collection<T> collection, int number) {
        List<T> list = new ArrayList<T>(collection);
        Collections.shuffle(list);

        return new HashSet<T>(list.subList(0, number));
    }
}

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4. generateMetricsDataWithPartialWrongTypes(String metricPostfix, boolean generateRandomTenant, long collectionTime)
5. getRandom(Collection collection)
6. nextItem(Collection items, Random random)
7. oneOf(Collection array)
8. peekRandom(Collection collection, Random rnd)
9. pickOneRandomly(Collection from)