此时equals仍未Object的,而非动态绑定时A类的equals
public class Test{
public static void main(String[] args) {
Object o1 = new A();
A o3 = new A();
System.out.println(o1.equals(o3));
}
}
class A{
public boolean equals(A a) {
System.out.println("yes");
return true;
}
}