java_可变参数构造器 Bulder模式

package com.test1.www;



class NutritionFacts {

	//必须

	private int servingSize;

	private int servings;

	//可选， Build类必须初始化

	private int calories;

	private int fat;

	private int sodium;

	private int carboohydrate;

	

	public int getServingSize() {

		return servingSize;

	}





	public int getServings() {

		return servings;

	}





	public int getCalories() {

		return calories;

	}





	public int getFat() {

		return fat;

	}





	public int getSodium() {

		return sodium;

	}





	public int getCarboohydrate() {

		return carboohydrate;

	}





	static class Builder {

		private int servingSize;

		private int servings;

		private int calories=0;

		private int fat=0;

		private int sodium=0;

		private int carboohydrate=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 sodium(int val) {

			sodium = val;

			return this;

		}



		public Builder carboohydrate(int val) {

			carboohydrate = val;

			return this;

		}

		public NutritionFacts build() {

			return new NutritionFacts(this);

		}



	}



	

	public NutritionFacts(Builder builder){

		servingSize = builder.servingSize;

		 calories=builder.calories;

		 fat=builder.fat;

		 sodium = builder.sodium;;

		 carboohydrate= builder.carboohydrate;

		

	}

}



public class Demo2 {

	public static void main(String[] args) {

		NutritionFacts nt = new NutritionFacts.Builder(240, 8).calories(20).carboohydrate(30).fat(20).sodium(2).build();

		

		System.out.println(nt.getServingSize());

		System.out.println(nt.getServings());

		System.out.println(nt.getCalories());

		System.out.println(nt.getFat());

		System.out.println(nt.getCarboohydrate());

		System.out.println(nt.getSodium());

	}

}