The Java compareto() method returns ClassCastException

Suppose I have an employee base class and a manager subclass, which extends employee Now suppose I create an object x of type employee and an object y of type manager, and call x.compareto (y) to trigger no exception and compare X and y, because the employee, that is, y, is forced to be an employee, but when I call y.compareto (x), I get a ClassCastException I need to know why this happens and how to prevent X. CompareTo (y) from executing, because X and Y come from different classes My idea is to use the getClass () method in the reflection class, as shown below:

if (getClass() != other.getClass()) 
throw new ClassCastException();

I also want to know if there are other ways to achieve this

Solution

You should implement CompareTo () in the Employee class and start it with the following command:

Employee o = (Employee)other;

Then continue to compare it with O – this will ensure that you compare the two employees (this is the lowest common standard)