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 getRandomNumber() {
    Random random = new Random();
    int num = random.nextInt(100);
    return num;/*from   www .ja  va 2s. co m*/
}

From source file:Main.java

private static String getOutTradeNo() {
    SimpleDateFormat format = new SimpleDateFormat("MMddHHmmss", Locale.getDefault());
    Date date = new Date();
    String key = format.format(date);

    Random r = new Random();
    key = key + r.nextInt();//w  ww .j  a v  a2 s  .c o m
    key = key.substring(0, 15);
    return key;
}

From source file:Main.java

public synchronized static String getOutTradeNo() {
    SimpleDateFormat format = new SimpleDateFormat("MMddHHmmss", Locale.getDefault());
    Date date = new Date();
    String key = format.format(date);
    Random r = new Random();
    key = key + r.nextInt();/* w w w .  j  av  a2  s . co  m*/
    key = key.substring(0, 15);
    return key;
}

From source file:Main.java

private static void printPassword() {
    String UPPER = "ABCDEFGHIJKLMNPQRSTUVWXYZ";
    String LOWER = "abcdefghijklmnpqrstuvwxyz";
    String NUMBER = "123456789";
    String SPECIAL = "!@#$%&*+?";
    Random randGen = new Random();

    StringBuffer buf = new StringBuffer();
    buf.append(LOWER.charAt(Math.abs(randGen.nextInt()) % LOWER.length()));
    buf.append(LOWER.charAt(Math.abs(randGen.nextInt()) % LOWER.length()));
    buf.append(NUMBER.charAt(Math.abs(randGen.nextInt()) % NUMBER.length()));
    for (int i = 0; i <= 4; i++) {
        buf.append(LOWER.charAt(Math.abs(randGen.nextInt()) % LOWER.length()));
    }/* w  w  w  . j  a va2s . co  m*/
    buf.append(UPPER.charAt(Math.abs(randGen.nextInt()) % UPPER.length()));
    buf.append(LOWER.charAt(Math.abs(randGen.nextInt()) % LOWER.length()));
    System.out.println(buf.toString());
}

From source file:Main.java

public static String getFileName(String suffix) {
    Date date = new Date(System.currentTimeMillis());
    SimpleDateFormat dateFormat = new SimpleDateFormat("'xc'_yyyyMMddHHmmss", Locale.CHINESE);
    String randomNumber = "_" + new Random().nextInt(10000);
    return dateFormat.format(date) + randomNumber + suffix;
}

From source file:Main.java

public static String getRandomFileName() {
    String rel = "";
    SimpleDateFormat formatter = new SimpleDateFormat("yyyyMMddHHmmss");
    Date curDate = new Date(System.currentTimeMillis());
    rel = formatter.format(curDate);/*  w  w  w  .j av  a  2  s .  com*/
    rel = rel + new Random().nextInt(1000);
    return rel;
}

From source file:Main.java

/**
 * Get a random color//from ww w. j  a va  2s  . c o  m
 *
 * @return Random color
 */
public static int getRandomColor() {
    Random random = new Random();
    return Color.rgb(random.nextInt(sColor_Range), random.nextInt(sColor_Range), random.nextInt(sColor_Range));
}

From source file:Main.java

public static String generateBoundary() {
    StringBuilder buffer = new StringBuilder();
    Random rand = new Random();
    int count = rand.nextInt(11) + 30; // a random size from 30 to 40
    for (int i = 0; i < count; i++) {
        buffer.append(MULTIPART_CHARS[rand.nextInt(MULTIPART_CHARS.length)]);
    }/*from w w  w. jav a2  s  .  c om*/
    return buffer.toString();
}

From source file:Main.java

/**
 * Generate a unicast MAC address./*from w ww .  j  av  a2  s  .c o  m*/
 * A unicast MAC address is the one with an even second hex.
 * i.e. x[0,2,4,6,8,A,C,E]:xx:xx:xx:xx:xx
 * 
 * @return Unicast MAC address
 */
public static String generateRandomMACAddress() {
    Random r = new Random();
    StringBuffer sb = new StringBuffer();
    sb.append(Integer.toHexString(r.nextInt(16)));
    int i = r.nextInt(16);
    while (i % 2 != 0)
        i = r.nextInt(16);
    sb.append(Integer.toHexString(i));
    while (sb.length() <= 12)
        sb.append(Integer.toHexString(r.nextInt()));
    String address = prepareMACAddress(sb.subSequence(0, 12).toString());
    if (address.equals("ff:ff:ff:ff:ff:ff"))
        return generateRandomMACAddress();
    return address;
}

From source file:Main.java

/**
 * Generates an array of random colors given the number of colors to create.
 * @param numOfColors, the number of colors to create.
 * @return an array of the random colors.
 *///from   w  w w  .j ava2s.c o m
public static int[] getRandomColors(int numOfColors) {
    Random random = new Random();
    int colors[] = new int[numOfColors];
    for (int i = 0; i < numOfColors; i++) {
        int r = random.nextInt(256);
        int g = random.nextInt(256);
        int b = random.nextInt(256);

        if ((r + g + b) > 450) {
            r = 110;
            b = 110;
            g = 110;
        }
        colors[i] = Color.rgb(r, g, b);
    }
    return colors;
}