题解 | #修改Data类的定义#

// 复习了一下对于构造方法为 private 构建对象的方法
// 1.写一个公共静态方法 在其中返回实例对象
// 2.反射
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        while (scanner.hasNextInt()) {
            int x = scanner.nextInt();
            int y = scanner.nextInt();
            Data data = Data.getInstance();
            data.setX(x);
            data.setY(y);
            System.out.println(data.getX() + data.getY());
        }
    }

}

class Data {

    private static Data instance;
    private int x;
    private int y;

    private Data() {}

    public static Data getInstance (){
        if(instance == null){
            instance = new Data();
        }
        return instance;
    }

    public int getX() {
        return x;
    }

    public int getY() {
        return y;
    }

    public void setX(int xnum) {
        x = xnum;
    }

    public void setY(int ynum) {
        y = ynum;
    }
}