Is there a more elegant way to iterate objects methods and test all those conditions Java

Question

I have the following code in Java and I want to minimize it or write it in a more concise way. Can you help me if this is feasible?

return( Objects.equals(obj1.getMeaning(), obj2.getMeaning())
        && Objects.equals(obj1.getModifies(), obj2.getModifies())
        && Objects.equals(obj1.getOriginalCommentString(), obj2.getOriginalCommentString())
        && Objects.equals(obj1.getReferences(), obj2.getReferences())
        && Objects.equals(obj1.getReturnDescription(), obj2.getReturnDescription())
        && Objects.equals(obj1.getReturnType(), obj2.getReturnType())
        && Objects.equals(obj1.getSuppressions(), obj2.getSuppressions())
        && Objects.equals(obj1.getTemplateTypeNames(), obj2.getTemplateTypeNames())
        && Objects.equals(obj1.getThisType(), obj2.getThisType())
        && Objects.equals(obj1.getThrownTypes(), obj2.getThrownTypes())
        && Objects.equals(obj1.getTypedefType(), obj2.getTypedefType())
        && Objects.equals(obj1.getType(), obj2.getType())
        && Objects.equals(obj1.getVersion(), obj2.getVersion())
        && Objects.equals(obj1.getVisibility(), obj2.getVisibility()))

Is it a good practice to give a list of the methods, as strings, and then create a map function to test them all one by one. I have read about reflection in Java but I am not that proficient.

If you decide to implement `equals`, read this first: https://stackoverflow.com/questions/27581/what-issues-should-be-considered-when-overriding-equals-and-hashcode-in-java — RaminS, Jan 22 '19 at 22:11
14 fields is too many, try to decompose them into several classes — Andrew Tobilko, Jan 22 '19 at 22:19
Have you looked into the BeanComparator utility class? https://commons.apache.org/proper/commons-beanutils/apidocs/org/apache/commons/beanutils/BeanComparator.html — JustinKSU, Jan 22 '19 at 22:34
You may be able to make some use of [Apache's EqualsBuilder](https://commons.apache.org/proper/commons-lang/apidocs/org/apache/commons/lang3/builder/EqualsBuilder.html) — Dawood ibn Kareem, Jan 22 '19 at 22:47

score 4 · Answer 1 · answered Jan 22 '19 at 22:21

4

You could have a method like:

<T> boolean equals(T obj1, T obj2, Iterable<? extends Function<? super T, ?>> fns) {
  for (Function<? super T, ?> fn : fns) {
    if (!Objects.equals(fn.apply(obj1), fn.apply(obj2))) {
      return false;
    }
  }
  return true;
}

and then call it like:

return equals(obj1, obj2, Arrays.asList(Thing::getMeaning, Thing::getModifies));

etc.

answered Jan 22 '19 at 22:21

Andy Turner

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This is growing on me. Any way to turn the last parameter into a vararg, so you don't need the call to asList? – Dawood ibn Kareem Jan 22 '19 at 22:49

Is there a more elegant way to iterate objects methods and test all those conditions Java

1 Answers1