Skip to content

Instantly share code, notes, and snippets.

Embed
What would you like to do?
オブジェクト生成、ビルダーパターンのサンプル
class NutritionFacts {
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 {
// 必須パラメータ
private final int servingSize;
private final int servings;
// オプショナルパラメータ。デフォルト値を入れておく。
private int calories = 0;
private int fat = 0;
private int sodium = 0;
private int carbohydrate = 0;
public Builder(int servingsSize, int servings) {
this.servingSize = servingsSize;
this.servings = servings;
}
public Builder calories(int calories) {
this.calories = calories;
return this;
}
public Builder fat(int fat) {
this.fat = fat;
return this;
}
public Builder sodium(int sodium) {
this.sodium = sodium;
return this;
}
public Builder carbohydrate(int carbohydrate) {
this.carbohydrate = carbohydrate;
return this;
}
public NutritionFacts build() {
return new NutritionFacts(this);
}
}
private NutritionFacts(Builder builder) {
servingSize = builder.servingSize;
servings = builder.servings;
calories = builder.calories;
fat = builder.fat;
sodium =builder.sodium;
carbohydrate = builder.carbohydrate;
}
}
class Main {
public static void main(String[] args) {
NutritionFacts cocaCola = new NutritionFacts.Builder(240, 8)
.calories(100)
.sodium(35)
.build();
}
}
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment