Immutable Type: public final fields vs. getter

java immutability
Daniel picture Daniel · Aug 3, 2011 · Viewed 13.7k times · Source

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

Peter Lawrey picture Peter Lawrey · Aug 3, 2011

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.

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