com.credibledoc.iso8583packer.bitmap.BitmapService Maven / Gradle / Ivy
package com.credibledoc.iso8583packer.bitmap;
import com.credibledoc.iso8583packer.exception.PackerRuntimeException;
import java.util.BitSet;
/**
* Static service. Converts Bitmap data.
*
* @author [email protected]
* @author Hani S. Kirollos
* @author Alwyn Schoeman
* @author Kyrylo Semenko
*/
public class BitmapService {
private BitmapService() {
throw new PackerRuntimeException("Please do not instantiate this static helper.");
}
/**
* Convert a BitSet into a binary field
*
* @param bitSet the BitSet
* @param bytesNumber number of bytes to return
* @return binary representation
*/
public static byte[] bitSet2byte(BitSet bitSet, int bytesNumber) {
int len = bytesNumber * 8;
byte[] bytes = new byte[bytesNumber];
for (int i = 0; i < len; i++) {
if (bitSet.get(i + 1)) {
bytes[i >> 3] |= (0x80 >> (i % 8));
}
}
if (len > 64) {
bytes[0] |= 0x80;
}
if (len > 128) {
bytes[8] |= 0x80;
}
return bytes;
}
/**
* Converts an ASCII representation of a Bitmap field
* into a Java BitSet
*
* @param b hex representation
* @param offset starting offset
* @param maxBits max number of bits (supports 8, 16, 24, 32, 48, 52, 64,.. 128 or 192)
* @return java BitSet object
*/
public static BitSet hex2BitSet(byte[] b, int offset, int maxBits) {
int shiftedLength = Character.digit((char) b[offset], 16) & 0x08;
int decidedLength = shiftedLength == 8 ? 128 : 64;
int len = maxBits > 64 ? decidedLength : maxBits;
BitSet bmap = new BitSet(len);
for (int i = 0; i < len; i++) {
int digit = Character.digit((char) b[offset + (i >> 2)], 16);
if ((digit & (0x08 >> (i % 4))) > 0) {
bmap.set(i + 1);
if (i == 65 && maxBits > 128) {
len = 192;
}
}
}
return bmap;
}
/**
* Converts a binary representation of a Bitmap field into a Java BitSet
*
* @param bytes binary representation
* @param offset staring offset
* @param maxBits max number of bits (supports 64,128 or 192)
* @return java BitSet object
*/
public static BitSet byte2BitSet(byte[] bytes, int offset, int maxBits) {
int decidedLength = (bytes[offset] & 0x80) == 0x80 ? 128 : 64;
int len = maxBits > 64 ? decidedLength : maxBits;
if (maxBits > 128 && bytes.length > offset + 8 && (bytes[offset + 8] & 0x80) == 0x80) {
len = 192;
}
BitSet bmap = new BitSet(len);
for (int i = 0; i < len; i++) {
int shifted = i >> 3;
int shiftedOffset = offset + shifted;
if (((bytes[shiftedOffset]) & (0x80 >> (i % 8))) > 0) {
bmap.set(i + 1);
}
}
return bmap;
}
}