Immutable Type: public final fields vs. getter

Question

I need a small Container-Class for storing some Strings which should be immutable. As String itself is an immutable type, I thought of something like that:

public final class Immu {   public final String foo;   public final String bar;    public Immu(final String foo, final String bar)   {     this.foo = foo;     this.bar = bar;   } } 

Many people seem to object using public fields at all and use Getters instead. IMHO this would be just boilerplate in this case, because String itself is immutable.

Other thoughts I may be missing on this one?

Answer 1

I would do what you believe is simplest and clearest. If you have a data value class which is only used by a restricted number of classes. esp a package local class. then I would avoid getter/setters and use package local or public fields.

If you have a class which you expect other modules/developers to use, following a getter/setter model may be a safer approach in the long run.

Answer 2

The problem is the uniform access principle. You may later need to modify foo so that it's obtained through a method instead of being fixed, and if you exposed the field instead of a getter, you'll need to break your API.