设计程序 public class Test { public static void main(String[] args){ Point p1=new Point(10,10); Point p2=p1.copy(); if(p1==p2) System.out.println("======="); if(p1.equals(p2)) System.out.println("++++++"); if(p1.equals(null)) System.out.println("******"); } }使输出结果为++++++

可以这样修改程序：

public class Test {
    public static void main(String[] args){
        Point p1 = new Point(10, 10);
        Point p2 = p1.copy();
        if(p1 == p2)
            System.out.println("=======");
        if(p1.equals(p2))
            System.out.println("++++++");
        if(p1.equals(null))
            System.out.println("******");
    }
}

class Point {
    private int x;
    private int y;

    public Point(int x, int y) {
        this.x = x;
        this.y = y;
    }

    public Point copy() {
        return new Point(this.x, this.y);
    }

    @Override
    public boolean equals(Object obj) {
        if (obj == null || !(obj instanceof Point)) {
            return false;
        }
        Point other = (Point) obj;
        return this.x == other.x && this.y == other.y;
    }
}

输出结果为：

++++++