Java Array Shuffle shuffle(final T[] array)

Description

Shuffle the elements in the given array.

License

Apache License

Declaration

public static <T> T[] shuffle(final T[] array) 

Method Source Code

//package com.java2s;
/**//from www.  j  a v  a2s  .  co m
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 */

import java.util.Random;

public class Main {
    private static final ThreadLocal<Random> RANDOM = new ThreadLocal<Random>() {
        @Override
        protected Random initialValue() {
            return new Random();
        }
    };

    /** Shuffle the elements in the given array. */
    public static <T> T[] shuffle(final T[] array) {
        if (array != null && array.length > 0) {
            final Random random = getRandom();
            for (int n = array.length; n > 1;) {
                final int randomIndex = random.nextInt(n);
                n--;
                if (n != randomIndex) {
                    final T tmp = array[randomIndex];
                    array[randomIndex] = array[n];
                    array[n] = tmp;
                }
            }
        }
        return array;
    }

    /** @return a pseudo random number generator. */
    public static Random getRandom() {
        return RANDOM.get();
    }
}

Related

1. shuffle(double[][] kernel, long seed)
2. shuffle(final A source, final Random random)
3. shuffle(final Object[] array)
4. shuffle(final Object[] values)
5. shuffle(final T[] arr)
6. shuffle(final T[] array)
7. shuffle(int a[])
8. shuffle(int arr[])
9. shuffle(int size, boolean reallyShuffle)