As its a pain to handle structural changes of the class in two places I often do:

class A {
  private B bChild;
  private C cChild;

  private Object[] structure() {
    return new Object[]{bChild, cChild};
  }

  int hashCode() {
      Arrays.hashCode(structure);
  }

  boolean equals(Object that) {
    return Arrays.equals(this.structure(), ((A)that).structure());
  }
}

What's bad about this approach besides boxing of primitives? Can it be improved?