Builder模式

package create_Destroy;//创建和销毁对象

//遇到多个构造器参数时使用构建器-Builder模式
public class BuilderPattern {
	private int servingSize;
	private int serving;
	private int calories;
	private int fat;
	private int sodium;
	private int carbothydrate;
	
	//内部静态类
	public  static class Builder{
		//必选参数
		private int servingSize;
		private int serving;
		//可选参数
		private int calories=0;
		private int fat=0;
		private int sodium=0;
		private int carbothydrate=0;
		
		public Builder(int servingSize ,int serving){
			this.serving = serving;
			this.servingSize  = servingSize;
		}
		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 carbothydrate(int val){
			carbothydrate = val;
			return this;
		}
		
		//关键方法
		public BuilderPattern builder(){
			return new BuilderPattern(this);
		}
	}
	
	private BuilderPattern(Builder builder){
		servingSize=builder.servingSize;
		serving=builder.serving;
		calories=builder.calories;
		fat=builder.fat;
		sodium=builder.sodium;
		carbothydrate=builder.carbothydrate;
	}
	
	//测试使用的输出方法：
	public void show(){
		System.out.print(servingSize+","+serving+","+calories+","+fat+","+sodium+","+carbothydrate);
	}
}

客户端代码：

		BuilderPattern coco =  new BuilderPattern.Builder(240, 80).calories(20).sodium(35).carbothydrate(27).builder();
		coco.show();