原文：http://www.x-beta.cn/programme/Java-hex-string-convert-7730.html

package com.nantian.iclient.atm.sdb;

public class Util {
public Util() {
}

/**
* 將指定byte數組以16進制的形式打印到控制臺
* @param hint String
* @param b byte[]
* @return void
*/
public static void printHexString(String hint, byte[] b) {
System.out.print(hint);
for (int i = 0; i < b.length; i++) {
String hex = Integer.toHexString(b[i] & 0xFF);
if (hex.length() == 1) {
hex = '0' + hex;
}
System.out.print(hex.toUpperCase() + " ");
}
System.out.println("");
}

/**
*
* @param b byte[]
* @return String
*/
public static String Bytes2HexString(byte[] b) {
String ret = "";
for (int i = 0; i < b.length; i++) {
String hex = Integer.toHexString(b[i] & 0xFF);
if (hex.length() == 1) {
hex = '0' + hex;
}
ret += hex.toUpperCase();
}
return ret;
}

/**
* 將兩個ASCII字符合成一個字節；
* 如："EF"--> 0xEF
* @param src0 byte
* @param src1 byte
* @return byte
*/
public static byte uniteBytes(byte src0, byte src1) {
byte _b0 = Byte.decode("0x" + new String(new byte[]{src0})).byteValue();
_b0 = (byte)(_b0 << 4);
byte _b1 = Byte.decode("0x" + new String(new byte[]{src1})).byteValue();
byte ret = (byte)(_b0 ^ _b1);
return ret;
}

/**
* 將指定字符串src，以每兩個字符分割轉換為16進制形式
* 如："2B44EFD9" --> byte[]{0x2B, 0x44, 0xEF, 0xD9}
* @param src String
* @return byte[]
*/
public static byte[] HexString2Bytes(String src){
byte[] ret = new byte[8];
byte[] tmp = src.getBytes();
for(int i=0; i<8; i++){
ret[i] = uniteBytes(tmp[i*2], tmp[i*2+1]);
}
return ret;
}

}