Example usage for java.util Random Random

Introduction

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

Prototype

public Random()

Source Link

Document

Creates a new random number generator.

Usage

From source file:Main.java

public static int getRandomArgb(int alpha, int begin, int last) {
    if (last > 255) {
        last = 255;/*from  w  ww  . ja  v a 2  s . co  m*/
    }
    int red = begin + new Random().nextInt(last - begin);
    int green = begin + new Random().nextInt(last - begin);
    int blue = begin + new Random().nextInt(last - begin);
    return Color.argb(alpha, red, green, blue);
}

From source file:Main.java

public static int rollDice(int number, int nSides) {
    int num = 0;/*www .  j  av  a2s . c om*/
    int roll = 0;
    Random r = new Random();
    if (nSides >= 3) {
        for (int i = 0; i < number; i++) {
            roll = r.nextInt(nSides) + 1;
            System.out.println("Roll is:  " + roll);
            num = num + roll;
        }
    } else {
        System.out.println("Error num needs to be from 3");
    }
    return num;
}

From source file:Main.java

/**
 * random in array/* w w w.  ja  v  a 2 s.  com*/
 *
 * @param array array which want to random
 * @return return a index of member in array
 */
public static int getRandom(int[] array) {
    return new Random().nextInt(array.length);
}

From source file:Main.java

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

    // Usually this should be a field rather than a method variable so
    // that it is not re-seeded every call.
    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) {
    String str = "abcdefghigklmnopkrstuvwxyzABCDEFGHIGKLMNOPQRSTUVWXYZ0123456789";
    Random random = new Random();
    StringBuffer sf = new StringBuffer();
    for (int i = 0; i < length; i++) {
        int number = random.nextInt(62);//0~61
        sf.append(str.charAt(number));//from   w  w w  .  j  av a 2s .  com

    }
    return sf.toString();
}

From source file:Main.java

public static <T> ArrayList<T> rand(ArrayList<T> population, int nSamplesNeeded) {
    Random r = new Random();
    ArrayList<T> ret = new ArrayList<T>();

    if (nSamplesNeeded > population.size() / 2) {
        ArrayList<T> original = new ArrayList<T>();
        original = population;//from   w  w w. j a  v a2s .  c  o m

        while (nSamplesNeeded > 0) {
            int rand = r.nextInt(original.size());
            if (rand < nSamplesNeeded) {
                ret.add(original.get(rand));
                original.remove(rand);
                nSamplesNeeded--;
            }
        }
        original.clear();
    } else
        ret = shuffle(population, nSamplesNeeded);

    return ret;
}

From source file:Main.java

/**
 * use and random value,maybe this can provide good experince
 *
 * @param min//from  w  ww. jav  a  2s .co  m
 * @param max
 * @return
 */
public static int getRandom(int min, int max) {
    Random random = new Random();
    return random.nextInt(Math.abs(max - min)) + min;
}

From source file:Main.java

public static String randomString(int stringLength) {
    char[] chars = "abcdefghijklmnopqrstuvwxyz".toCharArray();
    StringBuilder randomStringBuilder = new StringBuilder();
    Random random = new Random();
    for (int i = 0; i < stringLength; i++) {
        char c = chars[random.nextInt(chars.length)];
        randomStringBuilder.append(c);//  ww  w.j a  v  a  2  s. c  om
    }
    return randomStringBuilder.toString();
}

From source file:Main.java

public static int getRandom(int minNumber, int maxNumber) {
    Random rand = new Random();
    int randomNum = rand.nextInt(maxNumber - minNumber);
    return randomNum;
}

From source file:Main.java

public static String generateFilenameString() {
    SimpleDateFormat df = new SimpleDateFormat("yyyyMMddHHmmss");
    return df.format(new Date()) + "_" + new Random().nextInt(1000);
}