Java List Random Item getRandomElement(List myList)

Description

Get a random element from a list.

License

Apache License

Parameter

Parameter	Description
myList	current list

Declaration

public static <T> T getRandomElement(List<T> myList) 

Method Source Code

//package com.java2s;
/*//from ww  w  .  j av  a 2 s  .  c  om
 * #%L
 * ff4j-core
 * %%
 * Copyright (C) 2013 - 2014 Ff4J
 * %%
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * #L%
 */

import java.util.List;

public class Main {
    /**
     * Get a random element from a list.
     *
     * @param myList
     *      current list
     */
    public static <T> T getRandomElement(List<T> myList) {
        return myList.get(getRandomOffset(myList.size()));
    }

    /**
     * Get a random offset within map.
     *
     * @param size
     *      target list size
     * @return
     *      a random positive integer below size
     */
    public static int getRandomOffset(int size) {
        return (int) (Math.random() * Math.abs(size));
    }
}

Related

1. chooseRandomElement(List list, Random random)
2. computeCrossProduct(List> allArgPossibilities, int maximumSize)
3. findFirst(List list, T value, Comparator comparator)
4. generateInteger(int min, int maxInclusive, List excludedValues)
5. getRandomElement(final List list)
6. getRandomElementFromList(List l)
7. getRandomFromList(List list)
8. getRandomIdxList(int minIdx, int maxIdx)
9. getRandomIntBetween(int min, int max, List excludeList)