Randomizer.java Source code

Introduction

Here is the source code for Randomizer.java

Source

//package com.qlogic.commons.utils;

import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Random;
import java.util.Set;

public class Randomizer extends Random {

    /**
     * 
     */
    private static final long serialVersionUID = -4644693860576394313L;

    public static Randomizer getInstance() {
        return _instance;
    }

    public Randomizer() {
        super();
    }

    public Randomizer(long seed) {
        super(seed);
    }

    public int[] nextInt(int n, int size) {
        if (size > n) {
            size = n;
        }

        Set set = new LinkedHashSet();

        for (int i = 0; i < size; i++) {
            while (true) {
                Integer value = new Integer(nextInt(n));

                if (!set.contains(value)) {
                    set.add(value);

                    break;
                }
            }
        }

        int[] array = new int[set.size()];

        Iterator itr = set.iterator();

        for (int i = 0; i < array.length; i++) {
            array[i] = ((Integer) itr.next()).intValue();
        }

        return array;
    }

    public void randomize(char array[]) {
        int length = array.length;

        for (int i = 0; i < length - 1; i++) {
            int x = nextInt(length);
            char y = array[i];

            array[i] = array[i + x];
            array[i + x] = y;

            length--;
        }
    }

    public void randomize(int array[]) {
        int length = array.length;

        for (int i = 0; i < length - 1; i++) {
            int x = nextInt(length);
            int y = array[i];

            array[i] = array[i + x];
            array[i + x] = y;

            length--;
        }
    }

    public void randomize(List list) {
        int size = list.size();

        for (int i = 0; i <= size; i++) {
            int j = nextInt(size);
            Object obj = list.get(i);

            list.set(i, list.get(i + j));
            list.set(i + j, obj);

            size--;
        }
    }

    public void randomize(Object array[]) {
        int length = array.length;

        for (int i = 0; i < length - 1; i++) {
            int x = nextInt(length);
            Object y = array[i];

            array[i] = array[i + x];
            array[i + x] = y;

            length--;
        }
    }

    public String randomize(String s) {
        if (s == null) {
            return null;
        }

        char[] array = s.toCharArray();

        randomize(array);

        return new String(array);
    }

    private static Randomizer _instance = new Randomizer();

}