Example usage for java.util Random nextInt

Introduction

In this page you can find the example usage for java.util Random nextInt.

Prototype

public int nextInt(int bound)

Source Link

Document

Returns a pseudorandom, uniformly distributed int value between 0 (inclusive) and the specified value (exclusive), drawn from this random number generator's sequence.

Usage

From source file:Main.java

/**
 * Scramble oder of elements in a list./*from   w w  w . j a v  a  2 s  .c om*/
 *
 * @param list
 */
public static <E> void scrambleList(List<E> list) {
    if (isNotEmpty(list)) {
        Random generator = new Random();
        for (int i = 0; i < list.size(); i++) {
            int random = generator.nextInt(list.size());
            if (random != i) {
                //Util of vs.(swap)
                E objTemp = list.get(i);
                list.set(i, list.get(random));
                list.set(random, objTemp);
            }
        }
    }
}

From source file:com.mmj.app.common.util.SerialNumGenerator.java

/** ? */
public static String RandomString(int length) {
    String str = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
    Random random = new Random();
    StringBuffer buf = new StringBuffer();
    for (int i = 0; i < length; i++) {
        int num = random.nextInt(62);
        buf.append(str.charAt(num));//from w  w w  .j a  v a 2s . c  om
    }
    return buf.toString();
}

From source file:com.mmj.app.common.util.SerialNumGenerator.java

private static String getSuffix(Long id) {
    Long num = 1l;//from w  ww.j  ava 2 s .c om
    if (id != null) {
        num = id % 100000;// id??
    }

    Random random = new Random();
    StringBuffer suffixBuffer = new StringBuffer();
    suffixBuffer.append(String.valueOf(num)).append(random.nextInt(1000));
    return StringUtils.leftPad(suffixBuffer.toString(), 8, '0');
}

From source file:Main.java

public static int randInt(int min, int max) {

    // Usually this can be a field rather than a method variable
    Random rand = new Random();

    // nextInt is normally exclusive of the top value,
    // so add 1 to make it inclusive
    int randomNum = rand.nextInt((max - min) + 1) + min;

    return randomNum;
}

From source file:Main.java

public static int[] getMachineSelectionNumNo(int size, int numbers[]) {
    int length = numbers.length;
    int num[] = new int[size];
    Random random = new Random();
    List<Integer> list = new ArrayList<Integer>();
    while (list.size() < size) {
        int number = numbers[random.nextInt(length)];
        list.add(number);// w  w  w.  j a va 2s .c o m
    }

    for (int i = 0; i < list.size(); i++) {
        num[i] = list.get(i);
    }
    return num;
}

From source file:Main.java

/**
 * Using like subList() but it take randoms elements.
 *
 * @param list/* w w  w. j  a v  a2s  .com*/
 * @param sizeOfSubList
 */
public static <E> void randomSubList(List<E> list, int sizeOfSubList) {
    List<E> subList = Collections.emptyList();
    if (isNotEmpty(list) && list.size() > sizeOfSubList) {
        subList = new ArrayList<E>(sizeOfSubList);
        Random generator = new Random();
        for (int i = 0; i < sizeOfSubList; i++) {
            int random = generator.nextInt(list.size());
            subList.add(list.get(random));
            list.remove(random);
        }
    }
    list.clear();
    list.addAll(subList);
}

From source file:com.joyent.manta.http.ShufflingDnsResolver.java

/**
 * Shuffles an array of addresses that were returned from a DNS query.
 * Shuffle algorithm inspired by <a href="http://stackoverflow.com/a/1520212/33611">this stackoverflow post.</a>
 * @param addresses addresses to shuffle
 *///from   www. j  av a2 s . co  m
private static void shuffle(final InetAddress[] addresses) {
    // Only shuffle if we have 2 or more addresses
    if (addresses.length < 2) {
        return;
    }

    Random random = ThreadLocalRandom.current();

    for (int i = addresses.length - 1; i > 0; i--) {
        int index = random.nextInt(i + 1);
        // Simple swap
        InetAddress a = addresses[index];
        addresses[index] = addresses[i];
        addresses[i] = a;
    }
}

From source file:Main.java

/**
 * Returns a pseudo-random number between min and max, inclusive.
 * The difference between min and max can be at most
 * <code>Integer.MAX_VALUE - 1</code>.
 *
 * @param min Minimum value//from  w  ww  .  j  av  a 2s  . c  om
 * @param max Maximum value.  Must be greater than min.
 * @return Integer between min and max, inclusive.
 * @see java.util.Random#nextInt(int)
 */
public static int randInt(int min, int max) {

    // Usually this can be a field rather than a method variable
    Random rand = new Random();

    // nextInt is normally exclusive of the top value,
    // so add 1 to make it inclusive
    int randomNum = rand.nextInt((max - min) + 1) + min;

    return randomNum;
}

From source file:Main.java

public static String getRandomString(int length) {
    Random random = new Random();
    StringBuffer sb = new StringBuffer();
    for (int i = 0; i < length; i++) {
        int number = random.nextInt(3);
        long result = 0;
        switch (number) {
        case 0:/*from  www  .  ja  v a2  s .  c om*/
            result = Math.round(Math.random() * 25 + 65);
            sb.append(String.valueOf((char) result));
            break;
        case 1:
            result = Math.round(Math.random() * 25 + 97);
            sb.append(String.valueOf((char) result));
            break;
        case 2:
            sb.append(String.valueOf(new Random().nextInt(10)));
            break;
        }

    }
    return sb.toString();
}

From source file:de.onyxbits.raccoon.gui.Traits.java

protected static String saat(Random r) {
    byte[] b = { (byte) (r.nextInt(25) + 97), (byte) (r.nextInt(25) + 97), (byte) (r.nextInt(25) + 97),
            (byte) (r.nextInt(25) + 97), };
    return new String(b);
}