覆盖java ... Object类中的equals方法(Overriding an equals method from the java…Object class)

 我一直在试图弄清楚这个问题背后的原因，我一直在努力去理解为什么结果是这样。 我会解释我理解的一切，希望有人能够填补我的空白。 
 
 想象一下你有一堂课： 
 
public class Point {
    public boolean equals(Object o) {
        if (o == null || (!(o instanceof Point)) { // Let's call this method 1
            return false;
        }
        Point other = (Point) o;
        return x == other.x && y == other.y;
    }

    public boolean equals(Point p) { // Let's call this method 2
        if (p == null) {
            return false;
        }
        return x == p.x && y == p.y;
    }
}
 
 现在我们创建以下对象： 
 
Object o = new Object()

Point p = new Point(3,4)

Object op = new Point(3,4)
 
 如果我们打电话： 
 
p.equals(o) // this calls method 1

p.equals(p) // this calls method 2

p.equals(op) // this calls method 1
 
 但是，这是我感到困惑的地方。 
 
op.equals(o) // this calls method 1

op.equals(op) // this calls method 1

op.equals(p) // this calls method 1
 
 为什么最后一个调用方法1？ 方法2的方法签名不应该保证呼叫去那里吗？ 
 
 如果任何人都可以向我解释这将是伟大的！ 

I've been attempting to figure out the rationale behind this question and I have been struggling to see why the outcome is what it is. I will explain everything I understand and I hope someone will be able to fill in the blanks for me.
 
Imagine you have a class:
 
public class Point {
    public boolean equals(Object o) {
        if (o == null || (!(o instanceof Point)) { // Let's call this method 1
            return false;
        }
        Point other = (Point) o;
        return x == other.x && y == other.y;
    }

    public boolean equals(Point p) { // Let's call this method 2
        if (p == null) {
            return false;
        }
        return x == p.x && y == p.y;
    }
}
 
Now we create the following objects:
 
Object o = new Object()

Point p = new Point(3,4)

Object op = new Point(3,4)
 
If we call:
 
p.equals(o) // this calls method 1

p.equals(p) // this calls method 2

p.equals(op) // this calls method 1
 
However, this is where I get confused.
 
op.equals(o) // this calls method 1

op.equals(op) // this calls method 1

op.equals(p) // this calls method 1
 
Why does the last one call method 1? Shouldn't the method signature of method 2 warrant the call to go there?
 
If anyone could explain it to me that would be great!

原文：https://stackoverflow.com/questions/39934067