Using getters to instantiate collections in Java

Two facts:

• Collections are one of the most used data types in all kind of software projects.
• Java has been criticized as a very verbose programming language.

I realized that each time I used my collections I had to check if they were null. It is boring and it bloats my code.

In projects I have developed, for practical purposes there is no difference if a collection is null or empty. So, since some time ago I have adopted the practice to instantiate the class fields of collections data types in the corresponding getter method when the field is null.

public class Example{

   private List<Thing> things;
   
   public List<Thing> getThings(){
 
       if(things == null) things = new ArrayList<>();
 
       return things;
   }
}

Thus, I do not need null checking anymore because I access my collections through the corresponding getter method even when I am coding inside the same class, applying The Uniform Access Principle.

This convention has saved me a lot of time, has cleaned up my code for a better understanding and now my applications are more robust.

I hope this could be useful to you, but do not apply it blindly.

P.D.

After publish this post in LinkedIn a friend of mine pointed that this is a known pattern called Lazy initialization and with the new Optional type introduced in Java languaje the code could be even more elegant and syntetic:

public class Example{

    private List<Thing> things;
   
    public List<Thing> getThings(){
 
      return things = Optional.ofNullable(things).orElseGet(ArrayList::new);
    }
}

I like it :)