16进制与字符串的互转及转换为byte数组

import java.io.ByteArrayOutputStream;
import java.io.UnsupportedEncodingException;

public class TestToHex {
//switch0:bfaab9d8c1bfb1a8beaf
    private static String hexString = "0123456789ABCDEF";
    public static void main(String[] args) throws UnsupportedEncodingException {
        System.out.println(encode(new String("开关量报警".getBytes("gb2312"),"gb2312")));
        System.out.println(decode("BFAAB9D8C1BFB1A8BEAF"));
    }
    /*
     * 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) throws UnsupportedEncodingException {
        // 根据默认编码获取字节数组
        byte[] bytes = str.getBytes("gb2312");
        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) throws UnsupportedEncodingException {
        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 (new String(baos.toByteArray(),"gb2312").getBytes("utf-8"),"utf-8");
    }

        /*
	 * 将16进制的字符串装换为对应的byte数组，例如"A5000C5A81000000000000000000010E90AA" 转换为对应的数组形式
	 * 
	 * @param hexString
	 * @return 转换后的数组
	 */
	public byte[] hexStringToBytes(String hexString) {
		if (StringUtils.isEmpty(hexString)) {
			return null;
		}
		hexString = hexString.toUpperCase();
		int length = hexString.length() / 2;
		char[] hexChars = hexString.toCharArray();
		byte[] d = new byte[length];
		for (int i = 0; i < length; i++) {
			int pos = i * 2;
			d[i] = (byte) (charToByte(hexChars[pos]) << 4 | charToByte(hexChars[pos + 1]));
		}
		return d;
	}

	private byte charToByte(char c) {
		return (byte) "0123456789ABCDEF".indexOf(c);
	}
}