我想问就是标红的那一行我传入的是Integer类的数据(int自动装箱成Integer) 然后调用方法向上转型成了Object类 然后Object类按道理可以向下转型成String类啊?
package com.xyh.Demo;
class Point{
private Object x;
private Object y;
public Object getX() {
return x;
}
public void setX(Object x) {
this.x = x;
}
public Object getY() {
return y;
}
public void setY(Object y) {
this.y = y;
}
}
public class TestDemo {
public static void main(String[] args) {
// TODO Auto-generated method stub
Point p=new Point();
p.setX("东经100度");
[color=#FF0000]p.setY(10);[/color]
String x=(String)p.getX();
String y=(String)p.getY();
}
}