random Alphabetic - Java java.util

Java examples for java.util:Random String

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Description

random Alphabetic

Demo Code


//package com.java2s;
import java.util.Random;

public class Main {
    private static final Random RANDOM = new Random();

    public static String randomAlphabetic(int count) {
        return random(count, true, false);
    }/*  ww w  . j  a v a 2  s. c om*/

    public static String random(int count) {
        return random(count, false, false);
    }

    public static String random(int count, boolean letters, boolean numbers) {
        return random(count, 0, 0, letters, numbers);
    }

    public static String random(int count, int start, int end,
            boolean letters, boolean numbers) {
        return random(count, start, end, letters, numbers, null, RANDOM);
    }

    public static String random(int count, int start, int end,
            boolean letters, boolean numbers, char[] chars) {
        return random(count, start, end, letters, numbers, chars, RANDOM);
    }

    public static String random(int count, int start, int end,
            boolean letters, boolean numbers, char[] chars, Random random) {
        if (count == 0) {
            return "";
        } else if (count < 0) {
            throw new IllegalArgumentException(
                    "Requested random string length " + count
                            + " is less than 0.");
        }
        if ((start == 0) && (end == 0)) {
            end = 'z' + 1;
            start = ' ';
            if (!letters && !numbers) {
                start = 0;
                end = Integer.MAX_VALUE;
            }
        }

        StringBuffer buffer = new StringBuffer();
        int gap = end - start;

        while (count-- != 0) {
            char ch;
            if (chars == null) {
                ch = (char) (random.nextInt(gap) + start);
            } else {
                ch = chars[random.nextInt(gap) + start];
            }
            if ((letters && numbers && Character.isLetterOrDigit(ch))
                    || (letters && Character.isLetter(ch))
                    || (numbers && Character.isDigit(ch))
                    || (!letters && !numbers)) {
                buffer.append(ch);
            } else {
                count++;
            }
        }
        return buffer.toString();
    }

    public static String random(int count, String chars) {
        if (chars == null) {
            return random(count, 0, 0, false, false, null, RANDOM);
        }
        return random(count, chars.toCharArray());
    }

    public static String random(int count, char[] chars) {
        if (chars == null) {
            return random(count, 0, 0, false, false, null, RANDOM);
        }
        return random(count, 0, chars.length, false, false, chars, RANDOM);
    }
}

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