遇到多个构造器参数时要考虑用构造器

public class NutritionFacts{
private final int one;
private final int two;
private final int three;
public NutritionFacts(int one,int two,int three){
this.one = one;
this.two = two;

}
public NutritionFacts(int one){
this(one,0);
}
public NutritionFacts(int one,int two){
this(one,two,0);
}

}

//调用的时候 NutritionFacts nt = new NutritionFacts(0,0,0);
//缺点 ：重叠构造器模式，有许多参数的时候，难编写和阅读；

public class NutritionFacts{
private final int one;
private final int two;
private final int three;

private NutritionFacts(Bulider builder){
one = builder.one;
two = builder.two;
three = builder.three;
}

public static class Builder{
private  String name;
private  int one = 0;
private  int two = 0 ;
private  int three = 0;
public Builder(String name){
this.name = name;
}
public Builder one(int value){
one = value;
reture this;
}
public Builder two(int value){
two = value;
reture this;
}
public Builder two(int value){
two = value;
reture this;
}
//调用的时候，最后实例化外部类
public NutritionFacts build(){
return new NutritionFacts(this);
}

}

}