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

private static int getRandomNum(int n) {
    new Color();
    return new Random().nextInt(n);
}

From source file:Main.java

public static void shuffleArray(PointF[] ar, int length) {
    // If running on Java 6 or older, use `new Random()` on RHS
    Random rnd;//from  ww w .j a va 2s  .  c  o m
    if (Build.VERSION.SDK_INT >= 21)
        rnd = ThreadLocalRandom.current();
    else
        rnd = new Random();

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

From source file:Main.java

/**
 * This method generates a random n digit password, which contains at least one number, lower case alphabet, upper
 * case alphabet and as special character.
 *///from   w  w  w. j a va2s .  com
public static String generatePassword(int n) {

    Random rd = new Random();

    char lowerChars[] = "abcdefghijklmnopqrstuvwxyz".toCharArray();
    char upperChars[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ".toCharArray();
    char numbers[] = "0123456789".toCharArray();
    char specialChars[] = "~!@#$%^&*()-_=+[{]}|;:<>/?".toCharArray();

    List<Character> pwdLst = new ArrayList<Character>();
    for (int g = 0; g < 4; g++) {
        for (int z = 0; z < 1; z++) {
            if (g == 0) {
                pwdLst.add(numbers[rd.nextInt(10)]);
            } else if (g == 1) {
                pwdLst.add(lowerChars[rd.nextInt(26)]);
            } else if (g == 2) {
                pwdLst.add(upperChars[rd.nextInt(26)]);
            } else if (g == 3) {
                pwdLst.add(specialChars[rd.nextInt(26)]);
            }
        }
        if (pwdLst.size() == n) {
            break;
        }
        if (g + 1 == 4) {
            g = (int) Math.random() * 5;

        }
    }
    StringBuilder password = new StringBuilder();
    Collections.shuffle(pwdLst);
    for (int c = 0; c < pwdLst.size(); c++) {
        password.append(pwdLst.get(c));
    }
    return password.toString();
}

From source file:Main.java

public static byte[] getDHdataWithHash(byte[] hash, byte[] data) {
    int ost = (data.length + 20) % 16 > 0 ? 16 : 0;
    int size = ((20 + data.length) / 16) * 16 + ost;

    ByteBuffer buffer = ByteBuffer.allocate(size);
    buffer.put(hash);//from  w w w .ja  v a2 s .  com
    buffer.put(data);

    byte[] rand = new byte[size - hash.length - data.length];
    new Random().nextBytes(rand);
    buffer.put(rand);
    return buffer.array();
}

From source file:com.pamarin.income.util.StringRandom.java

public static String random2048bit() {
    byte[] r = new byte[256]; //Means 2048 bit
    Random random = new Random();
    random.nextBytes(r);/*from  ww w.  ja  v a 2s. co  m*/

    return Base64.encodeBase64String(r).replace("+", "_");
}

From source file:Main.java

public static String getRandomChar() {
    String[] arr = { "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", "e", "f", "g", "h", "i", "j",
            "k", "m", "n", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z", "A", "B", "C", "D", "E", "F",
            "G", "H", "I", "J", "K", "L", "M", "N", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z" };

    Random random = new Random();
    return arr[random.nextInt(57)];
}

From source file:Main.java

public static void saveBitmapToSD(Bitmap bitmap) {
    String root = Environment.getExternalStorageDirectory().toString();
    File myDir = new File(root + "/Download");
    myDir.mkdirs();/*from w w w  . j  a  va 2 s .c om*/
    Random generator = new Random();
    String fname = "Image-" + System.currentTimeMillis() + ".jpg";
    File file = new File(myDir, fname);
    if (file.exists())
        file.delete();
    try {
        FileOutputStream out = new FileOutputStream(file);
        bitmap.compress(Bitmap.CompressFormat.JPEG, 90, out);
        out.flush();
        out.close();

    } catch (Exception e) {
        e.printStackTrace();
    }
}

From source file:Main.java

public static String generateString(int length) {

    StringBuilder tmp = new StringBuilder();
    for (char ch = '0'; ch <= '9'; ++ch)
        tmp.append(ch);/* ww w  . j  a v  a 2  s  .  co m*/
    for (char ch = 'a'; ch <= 'z'; ++ch)
        tmp.append(ch);
    char[] symbols = tmp.toString().toCharArray();
    char[] buf = new char[length];
    Random random = new Random();

    for (int idx = 0; idx < buf.length; ++idx)
        buf[idx] = symbols[random.nextInt(symbols.length)];
    return new String(buf);
}

From source file:Main.java

/**
 * Get a random double number within a given range;
 *//*from w ww .  java  2  s.  c  o m*/
public static double getRandomDouble(double min, double max) throws Exception {
    double range = max - min;

    double ret;

    Random r = new Random();
    ret = r.nextDouble() * range;

    return ret;
}

From source file:Main.java

public static void saveImage(Bitmap bmp) {
    String root = Environment.getExternalStorageDirectory().toString();
    File myDir = new File(root + "/abcxyz");
    myDir.mkdirs();/*ww  w.ja v a  2 s  .  com*/
    Random generator = new Random();
    int n = 10000;
    n = generator.nextInt(n);
    String name = "Image-" + n + ".jpg";
    File file = new File(myDir, name);
    if (file.exists())
        file.delete();

    try {
        FileOutputStream out = new FileOutputStream(file);
        bmp.compress(Bitmap.CompressFormat.JPEG, 100, out);
        out.flush();
        out.close();
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
}