2.コンストラクタのパラメータが多い場合は、コンストラクタを考慮します.

public class NutirtionFacts {
	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 {
    	//필수
        private final int servingSize;
    	private final int servings;
        
        //선택 - 디폴트 값으로 초기화
        private final int calories = 0;
        private final int fat = 0;
        private final int sodium = 0;
        private final int carbohydrate = 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) {
        	this.servingSize = builder.servingSize;
            this.servings = builder.servings;
            this.calories = builder.calories;
            this.fat = builder.fat;
            this.carbohydrate = builder.carbohydrate;
            this.sodium = builder.sodium;
        }
        
    }
}


NutritionFacts cocaCola = new NutritionFacts.Builder(240, 8)
                          .calories(100)
                          .sodium(35)
                          .carbohydrate(27)
                          .builder();