java二进制,字节数组,字符,十六进制,BCD编码转换

// 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; } private final static byte[] hex = "0123456789ABCDEF".getBytes(); private static int parse(char c) { if (c >= 'a') return (c - 'a' + 10) & 0x0f; if (c >= 'A') return (c - 'A' + 10) & 0x0f; return (c - '0') & 0x0f; } // 从字节数组到十六进制字符串转换 public static String Bytes2HexString(byte[] b) { byte[] buff = new byte[2 * b.length]; for (int i = 0; i < b.length; i++) { buff[2 * i] = hex[(b[i] >> 4) & 0x0f]; buff[2 * i + 1] = hex[b[i] & 0x0f]; } return new String(buff); } // 从十六进制字符串到字节数组转换 public static byte[] HexString2Bytes(String hexstr) { byte[] b = new byte[hexstr.length() / 2]; int j = 0; for (int i = 0; i < b.length; i++) { char c0 = hexstr.charAt(j++); char c1 = hexstr.charAt(j++); b[i] = (byte) ((parse(c0) << 4) | parse(c1)); } return b; }