java中bit操作常用技巧<二>

最新推荐文章于 2024-07-12 04:29:16 发布

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/**
* @author canghailan 2012-03-02 21:31
*/
public class Bytes {
private static final char[] DIGITS = {
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'
};

public static String toBinaryString(byte b) {
int u = toUnsigned(b);
return new String(new char[]{
DIGITS[(u >>> 7) & 0x1],
DIGITS[(u >>> 6) & 0x1],
DIGITS[(u >>> 5) & 0x1],
DIGITS[(u >>> 4) & 0x1],
DIGITS[(u >>> 3) & 0x1],
DIGITS[(u >>> 2) & 0x1],
DIGITS[(u >>> 1) & 0x1],
DIGITS[u & 0x1]
});
}

public static String toBinaryString(byte... bytes) {
char[] buffer = new char[bytes.length * 8];
for (int i = 0, j = 0; i < bytes.length; ++i) {
int u = toUnsigned(bytes[i]);
buffer[j++] = DIGITS[(u >>> 7) & 0x1];
buffer[j++] = DIGITS[(u >>> 6) & 0x1];
buffer[j++] = DIGITS[(u >>> 5) & 0x1];
buffer[j++] = DIGITS[(u >>> 4) & 0x1];
buffer[j++] = DIGITS[(u >>> 3) & 0x1];
buffer[j++] = DIGITS[(u >>> 2) & 0x1];
buffer[j++] = DIGITS[(u >>> 1) & 0x1];
buffer[j++] = DIGITS[u & 0x1];
}
return new String(buffer);
}

public static String toHexString(byte b) {
int u = toUnsigned(b);
return new String(new char[]{
DIGITS[u >>> 4],
DIGITS[u & 0xf]
});
}

public static String toHexString(byte... bytes) {
char[] buffer = new char[bytes.length * 2];
for (int i = 0, j = 0; i < bytes.length; ++i) {
int u = toUnsigned(bytes[i]);
buffer[j++] = DIGITS[u >>> 4];
buffer[j++] = DIGITS[u & 0xf];
}
return new String(buffer);
}

private static int toUnsigned(byte b) {
return b < 0 ? b + 256 : b;
}
}