java surface,高效java-基础

public class NultritionFacts {

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 NulltritionFacts(int servingSize, int servings) {

this(servingSize, serving, 0);

}

public NulltritionFacts(int servingSize, int servings, int calories){

this(servingSize, servings, calories, 0);

}

public NulltritionFacts(int servingSize, int servings, int calories, int fat){

this(servingSize, servings, calories, fat, 0);

}

public NulltritionFacts(int servingSize, int servings, int calories, int fat, int sodium){

this(servingSize, servings, calories, fat, sodium, 0);

}

public NulltritionFacts(int servingSize, int servings, int calories, int fat, int sodium, int carbohydrate){

this.servingSize = servingSize;

this.serving = serving;

this.fat = fat;

this.sodium = sodium;

this.carbohydrate = carbohydrate;

}

//-----------------------使用构建器------------------------------------

public class NultritionFacts {

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 class Builder {

private final int servingSize;

private final int servings;

//初始化设置默认值

private int calories = 0;

private int fat = 0;

private int sodium = 0;

private int carbohydrate = 0;

public Builder(int servingSize, int serving) {

this.servingSize = servingSize;

this.serving = serving;

}

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 carbohydrate(int val) {

carbohydrate = val; return this;

}

public NulltritionFacts build() {

return new NulltritionFacts(this);

}

}

private NulltritionFacts(Builder builder) {

this.servingSize = builder.servingSize;

this.serving = builder.serving;

this.fat = builder.fat;

this.sodium = builder.sodium;

this.carbohydrate = builder.carbohydrate;

}