Spring Boot odd behavior with Java8

I started a project on SpringBoot to performs some tests.

What was interesting is the following.

I have a class which initializes some collections during construction(to avoid NPE).

So far so good if i test using JUnit but on SpringBoot i had to move the collection initialization outside the constructor...

On class throwing null pointer exception.

public TuneArtist() 
{ 
records = new HashSet<TuneRecord>();
credits = new HashSet<TuneCredit>();
releases = new HashSet<TuneRelease>();
}

The result code...

tuneArtist.setReleases(new HashSet<TuneRelease>());
info.getReleases().forEach(p -> tuneArtist.getReleases().
add(new TuneRelease(p.getId() , p.getName())));

tuneArtist.setCredits(new HashSet<TuneCredit>());
info.getCredits().forEach(p->tuneArtist.getCredits()
.add(new TuneCredit(p.getId() , p.getCreditName())));