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;

}