HEX값을 2의보수로 계산하여 Decimal로 출력하기

# HEX값을 2의보수로 계산하여 Decimal로 출력하기

# 2's complement hex number to decimal in java

-. HEX String을 2의보수로 계산하여 Decimal로 출력하는 소스

-. Hex to Decimal converter: https://www.rapidtables.com/convert/number/hex-to-decimal.html

1. Soruce

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57

package com.aimir.fep.bypass.sts.cmd;   import java.math.BigInteger;   public class Test {       public static void main(String[] args) {         String hexString = "FAA2A4E0";                  // 2's complement hex number to decimal         long resultDecial = Long.parseLong(hexToDec(hexString).toString());                  System.out.println("resultDecial: " + resultDecial);     }          public static Number hexToDec(String hex)  {            if (hex == null) {               throw new NullPointerException("hexToDec: hex String is null.");            }              // You may want to do something different with the empty string.            if (hex.equals("")) { return Byte.valueOf("0"); }              // If you want to pad "FFF" to "0FFF" do it here.              hex = hex.toUpperCase();              // Check if high bit is set.            boolean isNegative =               hex.startsWith("8") || hex.startsWith("9") ||               hex.startsWith("A") || hex.startsWith("B") ||               hex.startsWith("C") || hex.startsWith("D") ||               hex.startsWith("E") || hex.startsWith("F");              BigInteger temp;              if (isNegative) {               // Negative number               temp = new BigInteger(hex, 16);               BigInteger subtrahend = BigInteger.ONE.shiftLeft(hex.length() * 4);               temp = temp.subtract(subtrahend);            } else {               // Positive number               temp = new BigInteger(hex, 16);            }              // Cut BigInteger down to size.            if (hex.length() <= 2) { return (Byte)temp.byteValue(); }            if (hex.length() <= 4) { return (Short)temp.shortValue(); }            if (hex.length() <= 8) { return (Integer)temp.intValue(); }            if (hex.length() <= 16) { return (Long)temp.longValue(); }                        return temp;         }   }

2. Result

1 2 3 4 5 6 7 8 9 10 11 12 13 14

String hexString = "0004941E"; resultDecial: 300062   String hexString = "00000000"; resultDecial: 0   String hexString = "FFFFD8FB"; resultDecial: -9989   String hexString = "FFFEC788"; resultDecial: -79992   String hexString = "FAA2A4E0"; resultDecial: -90004256

→ P.S. https://stackoverflow.com/questions/6699275/2s-complement-hex-number-to-decimal-in-java