字符串、十六进制、byte数组互转

import java.io.ByteArrayOutputStream;

public class HexUtil {

	/**
	 * @param args
	 */
	public static void main(String[] args) {

		String str = "12345678";
		
		String hexStr = encode(str);
		
		System.out.println("字符串－>十六进制：" + hexStr);
		
		System.out.println("十六进制－>字符串：" + decode(hexStr));
		
	    System.out.println("十六进制->byte数组：" + HexString2Bytes(hexStr));
	    
	}

	public static String stringToHexString(String strPart) {
		String hexString = "";
		for (int i = 0; i < strPart.length(); i++) {
			int ch = (int) strPart.charAt(i);
			String strHex = Integer.toHexString(ch);
			hexString = hexString + strHex;
		}
		return hexString;
	}

	private static String hexString = "0123456789ABCDEF";

	/*
	 * 将字符串编码成16进制数字,适用于所有字符（包括中文）
	 */
	public static String encode(String str) {
		// 根据默认编码获取字节数组
		byte[] bytes = str.getBytes();
		StringBuilder sb = new StringBuilder(bytes.length * 2);
		// 将字节数组中每个字节拆解成2位16进制整数
		for (int i = 0; i < bytes.length; i++) {
			sb.append(hexString.charAt((bytes[i] & 0xf0) >> 4));
			sb.append(hexString.charAt((bytes[i] & 0x0f) >> 0));
		}
		return sb.toString();
	}

	/*
	 * 将16进制数字解码成字符串,适用于所有字符（包括中文）
	 */
	public static String decode(String bytes) {
		ByteArrayOutputStream baos = new ByteArrayOutputStream(
				bytes.length() / 2);
		// 将每2位16进制整数组装成一个字节
		for (int i = 0; i < bytes.length(); i += 2)
			baos.write((hexString.indexOf(bytes.charAt(i)) << 4 | hexString
					.indexOf(bytes.charAt(i + 1))));
		return new String(baos.toByteArray());
	}

	private 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;
	}

	public static byte[] HexString2Bytes(String src) {
		byte[] ret = new byte[6];
		byte[] tmp = src.getBytes();
		for (int i = 0; i < 6; ++i) {
			ret[i] = uniteBytes(tmp[i * 2], tmp[i * 2 + 1]);
		}
		return ret;
	}
}