Java Integer to Byte Array convertIntToByteArray(int value)

Description

convert Int To Byte Array

Declaration

public static byte[] convertIntToByteArray(int value) 

Method Source Code

//package com.java2s;

public class Main {
    private final static int[] sizeTable = { 9, 99, 999, 9999, 99999, 999999, 9999999, 99999999, 999999999,
            Integer.MAX_VALUE };/*from   w  w w  .  jav a2  s . co m*/
    private final static byte[] DigitTens = { '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '1', '1', '1', '1',
            '1', '1', '1', '1', '1', '1', '2', '2', '2', '2', '2', '2', '2', '2', '2', '2', '3', '3', '3', '3', '3',
            '3', '3', '3', '3', '3', '4', '4', '4', '4', '4', '4', '4', '4', '4', '4', '5', '5', '5', '5', '5', '5',
            '5', '5', '5', '5', '6', '6', '6', '6', '6', '6', '6', '6', '6', '6', '7', '7', '7', '7', '7', '7', '7',
            '7', '7', '7', '8', '8', '8', '8', '8', '8', '8', '8', '8', '8', '9', '9', '9', '9', '9', '9', '9', '9',
            '9', '9', };
    private final static byte[] DigitOnes = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '1', '2', '3',
            '4', '5', '6', '7', '8', '9', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '1', '2', '3', '4',
            '5', '6', '7', '8', '9', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '1', '2', '3', '4', '5',
            '6', '7', '8', '9', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '1', '2', '3', '4', '5', '6',
            '7', '8', '9', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '1', '2', '3', '4', '5', '6', '7',
            '8', '9', };
    private final static byte[] digits = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd',
            'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y',
            'z' };

    public static byte[] convertIntToByteArray(int value) {
        int originValue = value;
        int size = 0;
        if (value < 0) {
            value = -value;
        }

        while (value > sizeTable[size])
            size++;
        size++;
        if (originValue < 0)
            size++;

        int q, r;
        byte[] buf = new byte[size];
        if (originValue < 0) {
            buf[0] = '-';
        }
        int charPos = size;

        while (value >= 65536) {
            q = value / 100;
            r = value - ((q << 6) + (q << 5) + (q << 2));
            value = q;
            buf[--charPos] = DigitOnes[r];
            buf[--charPos] = DigitTens[r];
        }

        for (;;) {
            q = (value * 52429) >>> (16 + 3);
            r = value - ((q << 3) + (q << 1));
            buf[--charPos] = digits[r];
            value = q;
            if (value == 0)
                break;
        }
        return buf;
    }
}

Related

1. convertIntegersToBytes(int[] integers)
2. convertIntegerToByteArray(int value, int bytes, boolean revers)
3. convertIntToByteArray(int value, int numberOfBytes)
4. convertIntToByteArray(int[] rgb)
5. convertIntToBytes(int i)
6. fromIntToByte(int integer)