Running a method after the constructor of any derived class

Question

Let\'s say I have a Java class

abstract class Base {
    abstract void init();
    ...
}

and I know every derived class will have to call <

Answer 1

In addition to Bozho's recommendation, an application container is excellent for the task.

Mark your init() method with the javax.annotation.PostConstruct annotation and a rightly configured EJB or Spring container will execute the method after the dependency injections are finished, but before the object can be used by the application.

An example method:

@PostConstruct
public void init() { 
    // logic..
}

In an enterprise application you can open resources to for example the files system in the init() method. This initialization can throw exceptions and should not be called from a constructor.