import java.util.Arrays; import java.util.Objects; class X { private String[][] s = null; @Override public boolean equals(Object o) { if (this == o) return true; if (o == null || getClass() != o.getClass()) return false; final X x = (X) o; return Objects.deepEquals(s, x.s); } @Override public int hashCode() { return Arrays.deepHashCode(s); } }