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

If you're trying to use the array as a generic HashMap key, that's not going to work. Consider creating a custom wrapper object that holds the array, and whose equals(...) and hashcode(...) method returns the results from the java.util.Arrays methods. For example...

import java.util.Arrays;

public class MyByteArray {
   private byte[] data;

   // ... constructors, getters methods, setter methods, etc...


   @Override
   public int hashCode() {
      return Arrays.hashCode(data);
   }

   @Override
   public boolean equals(Object obj) {
      if (this == obj)
         return true;
      if (obj == null)
         return false;
      if (getClass() != obj.getClass())
         return false;
      MyByteArray other = (MyByteArray) obj;
      if (!Arrays.equals(data, other.data))
         return false;
      return true;
   }


}

Objects of this wrapper class will work fine as a key for your HashMap and will allow for clean use of equals(...) and hashCode(...) methods.