Java Collection Random Element oneOf(Collection array)

Description

one Of

License

Open Source License

Declaration

public static <T> T oneOf(Collection<T> array) 

Method Source Code

//package com.java2s;
/*//from ww  w .  j av a2s.  c o  m
 * Copyright (C) 2010-2011 VTT Technical Research Centre of Finland.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Random;

public class Main {
    private static Random random = new Random(100);

    public static <T> T oneOf(Collection<T> array) {
        List<T> list = new ArrayList<T>(array);
        return list.get(cInt(0, array.size() - 1));
    }

    public static int cInt() {
        return (int) Math.round(cDouble());
    }

    public static int cInt(int min, int max) {
        return (int) Math.round(cDouble(min, max));
    }

    public static double cDouble() {
        double min = Integer.MIN_VALUE;
        double max = Integer.MAX_VALUE;
        return cDouble(min, max);
    }

    public static double cDouble(double min, double max) {
        double diff = max - min;
        double rnd = random.nextDouble();
        rnd *= diff;
        rnd += min;
        return rnd;
    }
}

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5. nextItem(Collection items, Random random)
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