how to compare the Java Byte[] array?

Question

public class ByteArr {

    public static void main(String[] args){
        Byte[] a = {(byte)0x03, (byte)0x00, (byte)0x00, (byte)0x00};
        Byte[] b = {(byte)0x         


        

Answer 1

Arrays.equals is not enough for a comparator, you can not check the map contain the data. I copy the code from Arrays.equals, modified to build a Comparator.

class ByteArrays{
    public static  SortedMap newByteArrayMap() {
        return new TreeMap<>(new ByteArrayComparator());
    }

    public static SortedSet newByteArraySet() {
        return new TreeSet<>(new ByteArrayComparator());
    }

    static class ByteArrayComparator implements Comparator {
        @Override
        public int compare(byte[] a, byte[] b) {
            if (a == b) {
                return 0;
            }
            if (a == null || b == null) {
                throw new NullPointerException();
            }

            int length = a.length;
            int cmp;
            if ((cmp = Integer.compare(length, b.length)) != 0) {
                return cmp;
            }

            for (int i = 0; i < length; i++) {
                if ((cmp = Byte.compare(a[i], b[i])) != 0) {
                    return cmp;
                }
            }

            return 0;
        }
    }
}