best way to seperate common methods

Question

I have some common methods for two classes and maybe for others in the future. Therefore I do not want to copy same methods in all classes. I thought to create a utility class and put these methods inside and send the necessary data as a parameter. But I read about using utility class violate OOP.

As a second, I was thinking to apply strategy pattern but I do not need to change behaviour of the method in the runtime, it will work same for both classes therefore it looks it does not suit to my problem.

Do you have any idea what could be the best approach for this situation or which design pattern could be applied?

Create a baseclass with common methods, then extend baseclass. — JohannisK, May 12 '15 at 09:15
maybe try an abstract class with the common code and let both classes inherit from this — Dude, May 12 '15 at 09:16
possible duplicate of [Utility classes are evil?](http://stackoverflow.com/questions/3340032/utility-classes-are-evil) — pgrosslicht, May 12 '15 at 09:18
I was thinking about using inheritance but one of my firend told me it is not good approach to use inheritance for jsf classes. Therefore I was looking for another idea. — user1474111, May 12 '15 at 09:19
Use inheritance(base/abstract classes) only if its IS-A relationship, otherwise it will become a pain later. Try thinking in terms of injecting the dependency/behavior(Move this functionality to a new class) — Nitin Dandriyal, May 12 '15 at 09:36

score 2 · Answer 1 · answered May 12 '15 at 09:17

2

It's not bad to violate OOP for something that is really a utility class.

Almost all frameworks (spring, hibernate you_name_it) do that to some extend.

Furthermore, if you later plan to support your code, composition is much easier to refactor / support than to maintain inheritance in your classes.

answered May 12 '15 at 09:17

WeMakeSoftware

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this was the reason why I move to use composition rather than inheritance. – user1474111 May 12 '15 at 09:21

score 1 · Answer 2 · answered May 12 '15 at 09:20

public class Baseclass
{
    public Baseclass(){
        //init baseclass;
    }

    public void commonMethod(){
        //do stuff;
    }
}


public class AnyObject extends Baseclass
{
    public AnyObject(){
        super();
    }
}

Simple example

best way to seperate common methods

2 Answers2