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:FileList.java

public static void main(String[] args) {
    final int assumedLineLength = 50;
    File file = new File(args[0]);
    List<String> fileList = new ArrayList<String>((int) (file.length() / assumedLineLength) * 2);
    BufferedReader reader = null;
    int lineCount = 0;
    try {//from  ww  w.  j  ava2 s .  co m
        reader = new BufferedReader(new FileReader(file));
        for (String line = reader.readLine(); line != null; line = reader.readLine()) {
            fileList.add(line);
            lineCount++;
        }
    } catch (IOException e) {
        System.err.format("Could not read %s: %s%n", file, e);
        System.exit(1);
    } finally {
        if (reader != null) {
            try {
                reader.close();
            } catch (IOException e) {
            }
        }
    }
    int repeats = Integer.parseInt(args[1]);
    Random random = new Random();
    for (int i = 0; i < repeats; i++) {
        System.out.format("%d: %s%n", i, fileList.get(random.nextInt(lineCount - 1)));
    }
}

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From source file:Main.java

public static void main(String[] args) {
    long[] numbers = new long[] { 1, 2, 3, 4, 5 };
    Random id = new Random(numbers.length);

    String[] name = new String[] { "a", "b", "c", "d", "e" };

    for (int i = 0; i < numbers.length; i++) {
        int randomPosition = id.nextInt(4);
        long temp = numbers[i];
        numbers[i] = numbers[randomPosition];
        numbers[randomPosition] = temp;//from   w w  w .  ja va  2 s  .c o m
    }

    for (int i = 0; i < name.length; i++) {
        int randomPosition = id.nextInt(4);
        String temp = name[i];
        name[i] = name[randomPosition];
        name[randomPosition] = temp;
    }
    for (int i = 0; i < numbers.length; i++) {
        System.out.println(i + " ID = " + numbers[i] + " and name = " + name[i]);
    }
}

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From source file:TestCipher.java

public static void main(String args[]) throws Exception {
    Set set = new HashSet();
    Random random = new Random();
    for (int i = 0; i < 10; i++) {
        Point point = new Point(random.nextInt(1000), random.nextInt(2000));
        set.add(point);/*  w  ww  . java  2 s  . c o  m*/
    }
    int last = random.nextInt(5000);

    // Create Key
    byte key[] = password.getBytes();
    DESKeySpec desKeySpec = new DESKeySpec(key);
    SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
    SecretKey secretKey = keyFactory.generateSecret(desKeySpec);

    // Create Cipher
    Cipher desCipher = Cipher.getInstance("DES/ECB/PKCS5Padding");
    desCipher.init(Cipher.ENCRYPT_MODE, secretKey);

    // Create stream
    FileOutputStream fos = new FileOutputStream("out.des");
    BufferedOutputStream bos = new BufferedOutputStream(fos);
    CipherOutputStream cos = new CipherOutputStream(bos, desCipher);
    ObjectOutputStream oos = new ObjectOutputStream(cos);

    // Write objects
    oos.writeObject(set);
    oos.writeInt(last);
    oos.flush();
    oos.close();

    // Change cipher mode
    desCipher.init(Cipher.DECRYPT_MODE, secretKey);

    // Create stream
    FileInputStream fis = new FileInputStream("out.des");
    BufferedInputStream bis = new BufferedInputStream(fis);
    CipherInputStream cis = new CipherInputStream(bis, desCipher);
    ObjectInputStream ois = new ObjectInputStream(cis);

    // Read objects
    Set set2 = (Set) ois.readObject();
    int last2 = ois.readInt();
    ois.close();

    // Compare original with what was read back
    int count = 0;
    if (set.equals(set2)) {
        System.out.println("Set1: " + set);
        System.out.println("Set2: " + set2);
        System.out.println("Sets are okay.");
        count++;
    }
    if (last == last2) {
        System.out.println("int1: " + last);
        System.out.println("int2: " + last2);
        System.out.println("ints are okay.");
        count++;
    }
    if (count != 2) {
        System.out.println("Problem during encryption/decryption");
    }
}

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From source file:com.intuit.utils.PopulateUsers.java

public static void main(String[] args) {
    Date now = new Date();
    System.out.println("Current date is: " + now.toString());

    MongoClient mongo = new MongoClient("localhost", 27017);
    DB db = mongo.getDB("tweetsdb");
    DBCollection collection = db.getCollection("userscollection");
    WriteResult result = collection.remove(new BasicDBObject());

    int userIndex = 1;
    for (int i = 1; i <= 10; i++) {
        JSONObject userDocument = new JSONObject();
        String user = "user" + userIndex;
        userDocument.put("user", user);

        JSONArray followerList = new JSONArray();
        Random randomGenerator = new Random();
        for (int j = 0; j < 3; j++) {
            int followerId = randomGenerator.nextInt(10) + 1;
            // Assumption here is, a user will not be a follower on himself
            while (followerId == userIndex) {
                followerId = randomGenerator.nextInt(10) + 1;
            }/* ww w .  j a  va  2 s. c om*/

            String follower = "user" + followerId;
            if (!followerList.contains(follower)) {
                followerList.add(follower);
            }
        }
        userDocument.put("followers", followerList);

        JSONArray followingList = new JSONArray();
        for (int k = 0; k < 3; k++) {
            int followingId = randomGenerator.nextInt(10) + 1;
            // Assumption here is, a user will not be following his own tweets
            while (followingId == userIndex) {
                followingId = randomGenerator.nextInt(10) + 1;
            }

            String followingUser = "user" + followingId;
            if (!followingList.contains(followingUser)) {
                followingList.add(followingUser);
            }
        }
        userDocument.put("following", followingList);
        System.out.println("Json string is: " + userDocument.toString());
        DBObject userDBObject = (DBObject) JSON.parse(userDocument.toString());
        collection.insert(userDBObject);
        userIndex++;

    }

    //        try {
    //            FileWriter file = new FileWriter("/Users/dmurty/Documents/MongoData/usersCollection.js");
    //            file.write(usersArray.toJSONString());
    //            file.flush();
    //            file.close();
    //        } catch (IOException ex) {
    //            Logger.getLogger(PopulateUsers.class.getName()).log(Level.SEVERE, null, ex);
    //        } 
}

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From source file:MainClass.java

public static void main(String args[]) {
    Random randomNumbers = new Random(); // random number generator
    int face; // stores each random integer generated

    for (int i = 1; i <= 20; i++) {
        // pick random integer from 1 to 6
        face = 1 + randomNumbers.nextInt(6);

        System.out.printf("%d  ", face);

        // if i is divisible by 5, start a new line of output
        if (i % 5 == 0)
            System.out.println();
    }//from   w w w. j  a v  a 2s  .  co  m
}

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From source file:Main.java

License:asdf

public static void main(String[] args) {
    int howManyWords = 2;
    List<String> listOfWords = new ArrayList<>();
    Random random = new Random();
    listOfWords.addAll(Arrays.asList(randomMessages));
    List<String> selectedRandomMessages = new ArrayList<>();
    for (int i = 0; i < howManyWords; i++) {
        int randomNumber = random.nextInt(listOfWords.size());
        String randomItem = listOfWords.get(randomNumber);
        selectedRandomMessages.add(randomItem);
        listOfWords.remove(randomItem);//  w  ww.  jav a  2  s. c o m
    }
    System.out.println(selectedRandomMessages);
}

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From source file:QuickSort.java

/**
 * @param args//from  w ww  . jav a 2  s  .c  om
 */
public static void main(String[] args) {
    Integer[] array = new Integer[15];
    Random rng = new Random();
    int split = 10;
    for (int i = 0; i < split; i++) {
        array[i] = new Integer(rng.nextInt(100));
    }
    for (int i = split; i < array.length; i++) {
        array[i] = null;
    }

    System.out.println(Arrays.toString(array));

    QuickSort.sort(array, new Comparator<Integer>() {
        @Override
        public int compare(Integer o1, Integer o2) {
            return o1.compareTo(o2);
        };
    }, 0, split - 1);

    System.out.println(Arrays.toString(array));

}

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From source file:MathOps.java

public static void main(String[] args) {
    // Create a random number generator,
    // seeds with current time by default:

    Random rand = new Random();

    int i, j, k;/*from w  ww .  ja v a2  s .c  o  m*/

    // Choose value from 1 to 100:

    j = rand.nextInt(100) + 1;

    k = rand.nextInt(100) + 1;

    printInt("j", j);
    printInt("k", k);

    i = j + k;
    printInt("j + k", i);

    i = j - k;
    printInt("j - k", i);

    i = k / j;
    printInt("k / j", i);

    i = k * j;
    printInt("k * j", i);

    i = k % j;
    printInt("k % j", i);

    j %= k;
    printInt("j %= k", j);

    // Floating-point number tests:

    float u, v, w; // applies to doubles, too

    v = rand.nextFloat();

    w = rand.nextFloat();

    printFloat("v", v);
    printFloat("w", w);

    u = v + w;
    printFloat("v + w", u);

    u = v - w;
    printFloat("v - w", u);

    u = v * w;
    printFloat("v * w", u);

    u = v / w;
    printFloat("v / w", u);

    // the following also works for

    // char, byte, short, int, long,

    // and double:

    u += v;
    printFloat("u += v", u);

    u -= v;
    printFloat("u -= v", u);

    u *= v;
    printFloat("u *= v", u);

    u /= v;
    printFloat("u /= v", u);

}

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From source file:apidemo.APIDemo.java

public static void main(String[] args) throws InterruptedException, Exception {
    Random random = new Random();
    int uReqFeq = 1;

    while (uReqFeq < 101) {
        String strJSON = ObjectToString(new JSMessage((long) random.nextInt(10) + 1,
                (long) random.nextInt(10) + 11, "msg_" + Integer.toString(uReqFeq)));

        String res = sendPostJson("http://localhost:9494/api/nsservice/msg", strJSON, 10000);
        System.out.println("Result: " + res);

        ++uReqFeq;//from   ww  w  . j  a  va  2 s .co m
    }
}

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From source file:Main.java

public static void main(String[] args) {
    int maximum = 100;
    JFrame frame = new JFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    Integer[] oneRow = { 0, 0, 0, 0 };
    String[] headers = { "A", "B", "C", "D" };
    Integer[][] data = { oneRow, oneRow, oneRow, oneRow, oneRow, };
    DefaultTableModel model = new DefaultTableModel(data, headers);
    JTable table = new JTable(model);
    table.setDefaultRenderer(Object.class, new ProgressRenderer(0, maximum));
    table.setPreferredScrollableViewportSize(table.getPreferredSize());
    frame.add(new JScrollPane(table));
    frame.pack();// www  .j a  v a2 s.c  om
    frame.setVisible(true);
    new Thread(new Runnable() {
        @Override
        public void run() {
            Object waiter = new Object();
            synchronized (waiter) {
                int rows = model.getRowCount();
                int columns = model.getColumnCount();
                Random random = new Random(System.currentTimeMillis());
                boolean done = false;
                while (!done) {
                    int row = random.nextInt(rows);
                    int column = random.nextInt(columns);
                    Integer value = (Integer) model.getValueAt(row, column);
                    value++;
                    if (value <= maximum) {
                        model.setValueAt(value, row, column);
                        try {
                            waiter.wait(15);
                        } catch (InterruptedException e) {
                            e.printStackTrace();
                        }
                    }
                    done = true;
                    for (row = 0; row < rows; row++) {
                        for (column = 0; column < columns; column++) {
                            if (!model.getValueAt(row, column).equals(maximum)) {
                                done = false;
                                break;
                            }
                        }
                        if (!done) {
                            break;
                        }
                    }
                }
            }
        }
    }).start();
}

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