org.openlr.binary.reader.IntegerReader Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of openlr-binary Show documentation

The newest version!

package org.openlr.binary.reader;

import java.io.ByteArrayInputStream;
import java.io.IOException;

class IntegerReader {
    int readSignedInteger(int numberOfBytes, ByteArrayInputStream inputStream) throws IOException {
        byte[] bytes = inputStream.readNBytes(numberOfBytes);
        int value = 0;

        for (int i = 0; i < numberOfBytes; i++) {
            value = ((bytes[i] & 0xff) << ((numberOfBytes - i - 1) * 8)) | value;
        }

        if (((bytes[0] & 0xff) >> 7) == 1) {
            value -= (1 << (numberOfBytes * 8));
        }

        return value;
    }

    int readUnsignedInteger(int numberOfBytes, ByteArrayInputStream inputStream) throws IOException {
        byte[] bytes = inputStream.readNBytes(numberOfBytes);
        int value = 0;

        for (int i = 0; i < numberOfBytes; i++) {
            value = ((bytes[i] & 0xff) << ((numberOfBytes - i - 1) * 8)) | value;
        }

        return value;
    }
}