java - 是否在被视为组合的方法内从另一个类创建对象

Question

如果我有这门课

import java.util.Scanner;

public class SimpleCalc {

    private int x;
    private int y;
    private Scanner scan;

    public SimpleCalc() {
        scan = new Scanner(System.in);

        System.out.print("Please Enter The First Number: ");
        this.x = scan.nextInt();
        System.out.print("Please Enter The Second Number: ");
        this.y = scan.nextInt();
    }

}

此类使用组合概念，因为它具有来自另一个类“Scanner”的“scan”对象。

但是如果我在这样的方法中声明“scan”对象会怎么样:

public SimpleCalc() {
    Scanner scan = new Scanner(System.in);

    System.out.print("Please Enter The First Number: ");
    this.x = scan.nextInt();
    System.out.print("Please Enter The Second Number: ");
    this.y = scan.nextInt();
} 

这是否考虑了组合概念？

换句话说:组合概念仅适用于类还是也适用于方法？

Answer 1

如果您的问题是在设计模式的背景下并且特别与复合设计模式相关，那么简短的答案是否定的。

如GOF已描述:

"Compose objects into tree structure to represent part-whole hierarchies.Composite lets client treat individual objects and compositions of objects uniformly".

所以这不适用于方法。