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Question

I have a question about best practices to use properties in pojo class. Basically, I see that pojo class have getters/setters for private fields. It is easy to manipulate the properties but no so much flexibility(if we want to add additional property we will need to change minimum one class).

But there is another option to use properties(especially if you have too much properties) using Collection for them(Map, Set, etc.). In this case there is no need to change class if we want to add some new properties.The bad of this option, from my opinion, is that it will be a bit harder to get some kind of properties due to keys mistakes. What best practices could be applied for this topic?

Answer 1

The bad of this option, from my opinion, is that it will be a bit harder to get some kind of properties due to keys mistakes.

That's one of the problems with doing that, yes. Another is that using a property that doesn't exist becomes a runtime error instead of a compile-time error. And that unless all of the property values are the same type, you either have to use an untyped collection and cast everything all over the place ( f = (int)obj.get("foo"); ), or use several typed collections and always use the correct one ( f = obj.getInt("foo"); ).

What best practices could be applied for this topic?

Use proper properties, not a collection of name-value pairs. :-)