UUIDBasedOID.java

import java.math.BigInteger;
import java.util.UUID;
/** Code from
 *  https://github.com/cchigoriwa/jaxcsd/blob/master/jaxcsd-api/src/main/java/zw/co/hitrac/jaxcsd/api/util/UUIDBasedOID.java
 */
public class UUIDBasedOID {

    protected static final String OID_PREFIX = "2.25";    // {joint-iso-itu-t uuid(25) <uuid-single-integer-value>}
    
    protected UUID uuid;
    protected String oid;

    /**
     * random generate a 2.25 oid
     */
    public UUIDBasedOID() {
        uuid = UUID.randomUUID();
        oid = createOIDFromUUIDCanonicalHexString(uuid.toString());
    }

    public UUIDBasedOID(String uuid) {
        oid = createOIDFromUUIDCanonicalHexString(uuid);
    }

    /**
     * generate a 2.25 oid from a given uuid
     * @param uuid 
     */
    public String getOID() {
        return oid;
    }

    public UUID getUUID() {
        return uuid;
    }

    public static BigInteger makeBigIntegerFromUnsignedLong(long unsignedLongValue) {
        BigInteger bigValue;
        if (unsignedLongValue < 0) {
            unsignedLongValue = unsignedLongValue & Long.MAX_VALUE;
            bigValue = BigInteger.valueOf(unsignedLongValue);
            bigValue = bigValue.setBit(63);
        } else {
            bigValue = BigInteger.valueOf(unsignedLongValue);
        }
        //System.err.println("makeBigIntegerFromUnsignedLong(): bigValue = "+com.pixelmed.utils.HexDump.dump(bigValue.toByteArray()));
        return bigValue;
    }

    public static String createOIDFromUUIDCanonicalHexString(String hexString) throws IllegalArgumentException {
        UUID uuid = UUID.fromString(hexString);
        long leastSignificantBits = uuid.getLeastSignificantBits();
        long mostSignificantBits = uuid.getMostSignificantBits();
        BigInteger decimalValue = makeBigIntegerFromUnsignedLong(mostSignificantBits);
        decimalValue = decimalValue.shiftLeft(64);
        BigInteger bigValueOfLeastSignificantBits = makeBigIntegerFromUnsignedLong(leastSignificantBits);
        decimalValue = decimalValue.or(bigValueOfLeastSignificantBits);   // not add() ... do not want to introduce question of signedness of long
        return OID_PREFIX + "." + decimalValue.toString();
    }

    public static final void main(String arg[]) {
        //隨機建立 2.25 OID
        System.out.println(new UUIDBasedOID().getOID());
        //根據已有之guid建立2.25 OID
        System.out.println(new UUIDBasedOID("4dfce014-02d4-4b54-ad2d-d70c847a040f").getOID());
    }
}