Java BigDecimal to convertBigDecimalToSQLBigNum(BigDecimal bd, int targetLength, int targetScale)

Description

convert Big Decimal To SQL Big Num

License

Apache License

Declaration

public static byte[] convertBigDecimalToSQLBigNum(BigDecimal bd, int targetLength, int targetScale) 

Method Source Code

//package com.java2s;
//  Licensed under the Apache License, Version 2.0 (the "License");

import java.math.BigDecimal;

public class Main {
    static private final int[] powersOfTen = { 10, 100, 1000, 10000 };

    public static byte[] convertBigDecimalToSQLBigNum(BigDecimal bd, int targetLength, int targetScale) {
        byte[] sourceData = bd.setScale(targetScale, BigDecimal.ROUND_DOWN).unscaledValue().toString().getBytes(); // add
        // trailing
        // 0s,//from  www .j  a  v a 2  s .c om
        // remove decimal point,
        // get the chars
        byte[] targetData = new byte[targetLength];
        int[] targetInShorts = new int[targetLength / 2];

        int length;
        int temp;
        int tarPos = 1;

        // remove leading 0s and sign character
        int zeros = 0;
        while (zeros < sourceData.length && (sourceData[zeros] == '0' || sourceData[zeros] == '-'))
            zeros++;

        // convert from characters to values
        for (int i = zeros; i < sourceData.length; i++)
            sourceData[i] -= '0';

        length = sourceData.length - zeros; // we have a new length

        // iterate through 4 bytes at a time
        for (int i = 0; i < length; i += 4) {
            int temp1 = 0;
            int j = 0;

            // get 4 bytes worth of data or as much that is left
            for (j = 0; j < 4 && i + j < length; j++)
                temp1 = temp1 * 10 + sourceData[zeros + i + j];

            int power = powersOfTen[j - 1]; // get the power of ten based on how
            // many digits we got

            temp = targetInShorts[0] * power + temp1; // move the current
            // digits over and then
            // add our new value in
            targetInShorts[0] = temp & 0xFFFF; // we save only up to 16bits --
            // the rest gets carried over

            // we do the same thing for the rest of the digits now that we have
            // an upper bound
            for (j = 1; j < targetInShorts.length; j++) {
                int t = (temp & 0xFFFF0000) >> 16;
                temp = targetInShorts[j] * power + t;

                targetInShorts[j] = temp & 0xFFFF;
            }

            int carry = (temp & 0xFFFF0000) >> 16;
            if (carry > 0) {
                targetInShorts[tarPos++] = carry;
            }
        }

        // convert the data back to bytes
        for (int i = 0; i < targetInShorts.length; i++) {
            //         targetData[i * 2] = (byte) ((targetInShorts[i] & 0xFF00) >> 8);
            //         targetData[i * 2 + 1] = (byte) (targetInShorts[i] & 0xFF);
            targetData[i * 2] = (byte) (targetInShorts[i] & 0xFF);
            targetData[i * 2 + 1] = (byte) ((targetInShorts[i] & 0xFF00) >> 8);
        }

        // add sign
        if ((bd.signum() < 0))
            targetData[targetData.length - 2] |= 0x80;

        return targetData;
    }
}

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6. convertBigDecimalToString(BigDecimal bigValue)
7. convertDoubleToBigDecimal(Double value)
8. convertDoubleToBigDecimal(final Double score, final int decimalPlaces)
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