Question

public abstract ClassName
{

 // methods
 // setters & getters...???

}

Answer 1

The short answer: yes:

public abstract class ClassName {
    private String field;

    public String getString() {
        return field;
    }

    public void setString(String field) {
        this.field = field;
    }
}

More extended answer (I’m not sure that it’s actual for you right now):

You should realize that these methods (if they are not declared with final modifier) can be overriden in subclasses. That’s why it’s important to think about methods contracts and document them carefully. If one of the methods of your abstract class invokes another its method then this fact should also be documented.

All protected and public methods (and constants, and in very very seldom cases – protected fields) of your abstract class become a part of your API. Thus, other developers can use them and it’s not very easy to change them.

About best practices:

1) Think twice before making your class Serializable – this will make all subclasses searializable too and (if you want to produce not potentially broken program) you should care about possible serialization of any of the subclasses.

2) The same is actual for implementing Cloneable (do not better implement it in a top-level abstract class).

3) You should provide correct equals and hashCode implementation taking into account that 2 subclasses can be compared with your implementation from the abstract class.

4) Think about providing natural ordering (i.e. implementing Comparable interface). It’s often a good idea if there is a real natural ordering exists.