Embedding the Builder Interface in an Effective Java Book

Question

I read "Effective Java" by Joshua Bloch. At the top of page 16, he says:

Note that our NutritionFacts.Builder class could be declared to implement Builder<NutritionFacts>. 

But how can "Builder" implement the "Builder" interface, because there is a collision of the namespace, for example:

 public static class Builder implements Builder<NutritionFacts>... 

Should I rename the inner static class to something like NutritionFacts.NutritionBuilder or what?

Here is the creator template that he provided:

 // Builder Pattern public class NutritionFacts { private final int servingSize; private final int servings; private final int calories; private final int fat; private final int sodium; private final int carbohydrate; public static class Builder { // Required parameters private final int servingSize; private final int servings; // Optional parameters - initialized to default values private int calories = 0; private int fat = 0; private int carbohydrate = 0; private int sodium = 0; public Builder(int servingSize, int servings) { this.servingSize = servingSize; this.servings = servings; } public Builder calories(int val) { calories = val; return this; } public Builder fat(int val) { fat = val; return this; } public Builder carbohydrate(int val) { carbohydrate = val; return this; } public Builder sodium(int val) { sodium = val; return this; } public NutritionFacts build() { return new NutritionFacts(this); } } private NutritionFacts(Builder builder) { servingSize = builder.servingSize; servings = builder.servings; calories = builder.calories; fat = builder.fat; sodium = builder.sodium; carbohydrate = builder.carbohydrate; } } 

Answer 1

You can fully define the name of the interface.

i.e:

 public static class Builder implements my.package.Builder<NutritionFacts> {