16進制,byte,byte數組之間裝換

package com.rmt.updata;

import java.util.Locale;

public class Hex {
	/**
	 * 字符串轉換成十六進制字符串
	 * @param String
	 *            str 待轉換的ASCII字符串
	 * @return String 每個Byte之間空格分隔，如: [61 6C 6B]
	 */
	public static String str2HexStr(String str) {
		char[] chars = "0123456789ABCDEF".toCharArray();
		StringBuilder sb = new StringBuilder("");
		byte[] bs = str.getBytes();
		int bit;

		for (int i = 0; i < bs.length; i++) {
			bit = (bs[i] & 0x0f0) >> 4;
			sb.append(chars[bit]);
			bit = bs[i] & 0x0f;
			sb.append(chars[bit]);
			sb.append(' ');
		}
		return sb.toString().trim();
	}

	/**
	 * 十六進制轉換字符串
	 * @param String
	 *            str Byte字符串(Byte之間無分隔符 如:[616C6B])
	 * @return String 對應的字符串
	 */
	public static String hexStr2Str(String hexStr) {
		String str = "0123456789ABCDEF";
		char[] hexs = hexStr.toCharArray();
		byte[] bytes = new byte[hexStr.length() / 2];
		int n;

		for (int i = 0; i < bytes.length; i++) {
			n = str.indexOf(hexs[2 * i]) * 16;
			n += str.indexOf(hexs[2 * i + 1]);
			bytes[i] = (byte) (n & 0xff);
		}
		return new String(bytes);
	}

	/**
	 * bytes轉換成十六進制字符串
	 * @param byte[] b byte數組
	 * @return String 每個Byte值之間空格分隔
	 */
	public static String byte2HexStr(byte[] b) {
		String stmp = "";
		StringBuilder sb = new StringBuilder("");
		for (int n = 0; n < b.length; n++) {
			stmp = Integer.toHexString(b[n] & 0xFF);
			sb.append((stmp.length() == 1) ? "0" + stmp : stmp);
			// sb.append(" ");
		}
		return sb.toString().toUpperCase(Locale.ENGLISH).trim();
	}

	/**
	 * bytes字符串轉換爲Byte值
	 * @param String
	 *            src Byte字符串，每個Byte之間沒有分隔符
	 * @return byte[]
	 */
	public static byte[] hexStr2Bytes(String src) {
		int m = 0, n = 0;
		int l = src.length() / 2;
		System.out.println(l);
		byte[] ret = new byte[l];
		for (int i = 0; i < l; i++) {
			m = i * 2 + 1;
			n = m + 1;
			ret[i] = Byte.decode("0x" + src.substring(i * 2, m) + src.substring(m, n));
		}
		return ret;
	}

	/**
	 * String的字符串轉換成unicode的String
	 * @param String
	 *            strText 全角字符串
	 * @return String 每個unicode之間無分隔符
	 * @throws Exception
	 */
	public static String strToUnicode(String strText) throws Exception {
		char c;
		StringBuilder str = new StringBuilder();
		int intAsc;
		String strHex;
		for (int i = 0; i < strText.length(); i++) {
			c = strText.charAt(i);
			intAsc = (int) c;
			strHex = Integer.toHexString(intAsc);
			if (intAsc > 128)
				str.append("\\u" + strHex);
			else
				str.append("\\u00" + strHex);  // 低位在前面補00
		}
		return str.toString();
	}

	/**
	 * unicode的String轉換成String的字符串
	 * @param String
	 *            hex 16進制值字符串 （一個unicode爲2byte）
	 * @return String 全角字符串
	 */
	public static String unicodeToString(String hex) {
		int t = hex.length() / 6;
		StringBuilder str = new StringBuilder();
		for (int i = 0; i < t; i++) {
			String s = hex.substring(i * 6, (i + 1) * 6);
			String s1 = s.substring(2, 4) + "00";          // 高位需要補上00再轉
			String s2 = s.substring(4);                    // 低位直接轉
			int n = Integer.valueOf(s1, 16) + Integer.valueOf(s2, 16);  // 將16進制的string轉爲int
			char[] chars = Character.toChars(n);           // 將int轉換爲字符
			str.append(new String(chars));
		}
		return str.toString();
	}
}