ByteUtil

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/**
 * 字节转化工具类
 * 
 * @author chenxin
 * @version [版本号, 2012-5-21]
 * @see [相关类/方法]
 * @since [产品/模块版本]
 */
public class ByteUtil {

	/**
     * 把16进制字符串转换成字节数组
     * <功能详细描述>
     * @param hex String
     * @return byte[]
     * @see [类、类#方法、类#成员]
     */
    public static byte[] hexString2Bytes(String hex)
    {
        int len = (hex.length() / 2);
        byte[] result = new byte[len];
        char[] achar = hex.toCharArray();
        for (int i = 0; i < len; i++)
        {
            int pos = i * 2;
            result[i] = (byte)(char2Byte(achar[pos]) << 4 | char2Byte(achar[pos + 1]));
        }
        return result;
    }
    
    private static byte char2Byte(char ch)
    {
        switch (ch)
        {
            case '0':
                return 0x00;
            case '1':
                return 0x01;
            case '2':
                return 0x02;
            case '3':
                return 0x03;
            case '4':
                return 0x04;
            case '5':
                return 0x05;
            case '6':
                return 0x06;
            case '7':
                return 0x07;
            case '8':
                return 0x08;
            case '9':
                return 0x09;
            case 'a':
                return 0x0A;
            case 'b':
                return 0x0B;
            case 'c':
                return 0x0C;
            case 'd':
                return 0x0D;
            case 'e':
                return 0x0E;
            case 'f':
                return 0x0F;
        }
        return 0x00;
    }
    
    /**
     * 字节数组 转化成 16进制字符串
     * <功能详细描述>
     * @param b byte[]
     * @return String
     * @see [类、类#方法、类#成员]
     */
    public static String bytes2hexString(byte[] b)
    {
        String stmp = null;
        StringBuffer buf = new StringBuffer();
        
        for (int n = 0; n < b.length; n++)
        {
            stmp = Integer.toHexString(b[n] & 0xff);
            if (1 == stmp.length())
            {
                stmp = "0" + stmp;
            }
            
            buf.append(stmp);
        }
        return buf.toString();
    }


    // 整数到字节数组转换
    public static byte[] int2bytes(int n)
    {
        byte[] ab = new byte[4];
        ab[0] = (byte)(0xff & n);
        ab[1] = (byte)((0xff00 & n) >> 8);
        ab[2] = (byte)((0xff0000 & n) >> 16);
        ab[3] = (byte)((0xff000000 & n) >> 24);
        return ab;
    }
    
    // 字节数组到整数的转换
    public static int bytes2int(byte b[])
    {
        int s = 0;
        s = ((((b[0] & 0xff) << 8 | (b[1] & 0xff)) << 8) | (b[2] & 0xff)) << 8 | (b[3] & 0xff);
        return s;
    }
    
    // 字节转换到字符
    public static char byte2char(byte b)
    {
        return (char)b;
    }




}