TALK IS CHEAP SHOW ME THE CODE!

package chapter2.item02;

public class NutritionFacts {

    // required
    private final int servingSize;
    private final int servings;

    // optional
    private int calories     = 0;
    private int fat          = 0;
    private int sodium       = 0;
    private int carbohydrate = 0;

    private NutritionFacts(Builder builder) {
        this.servingSize  = builder.servingSize;
        this.servings     = builder.servings;
        this.calories     = builder.calories;
        this.fat          = builder.fat;
        this.sodium       = builder.sodium;
        this.carbohydrate = builder.carbohydrate;
    }

    @Override
    public String toString() {
        return "NutritionFacts{" +
                "servingSize=" + servingSize +
                ", servings=" + servings +
                ", calories=" + calories +
                ", fat=" + fat +
                ", sodium=" + sodium +
                ", carbohydrate=" + carbohydrate +
                '}';
    }

    public static class Builder {

        // required
        private final int servingSize;
        private final int servings;

        // optional
        private int calories     = 0;
        private int fat          = 0;
        private int sodium       = 0;
        private int carbohydrate = 0;

        public Builder(int servingSize, int servings) {
            this.servingSize = servingSize;
            this.servings    = servings;
        }

        public Builder calories(int val) {
            this.calories = val;
            return this;
        }

        public Builder fat(int val) {
            this.fat = val;
            return this;
        }

        public Builder sodium(int val) {
            this.sodium = val;
            return this;
        }

        public Builder carbohydrate(int val) {
            this.carbohydrate = val;
            return this;
        }

        public NutritionFacts build() {
            return new NutritionFacts(this);
        }

    }

}

class NutritionFactsClient {

    public static void main(String[] args) {
        NutritionFacts nutritionFacts = new NutritionFacts.Builder(240,8)
                .calories(100)
                .sodium(35)
                .carbohydrate(27)
                .build();
        System.out.println(nutritionFacts);
    }

}