Casting an Object to a Class

[Larry Frissell]

The following code is giving me compile errors on line 11, when I try to cast an Object to an Employee class. If I made a class without extending ArrayList, casting would not be a problem. I am not sure what the rules are that are causing the compile errors when I extend ArrayList.

  
public class Staff<Employee> extends ArrayList {
Employee e;
       @Override
public boolean add(Object o){   
   boolean result=false;
    e= (Employee)o;
    if(e.getClass().isInstance(o)){
       System.out.println("Is an Employee");
       super.add(o);
        e.getName(); //compile errors      
      result = true;
    }
   return result;
   }

   
}  

Error
cannot find symbol
symbol : method getName()
location: class java.lang.Object
e.getName();// compile errors

[Kevin Workman]

There's a lot wrong there, but let me just get the stupid question out of the way:

Are you sure this is exactly the code you're running? Are you sure you aren't calling o.getName()?

Posting an SSCCE would help clear up any confusion about what you're doing, which would help you get better assistance.

[Rob Spoor]

Larry Frissell wrote:

public class Staff<Employee> extends ArrayList {

Don't you mean

public class Staff extends ArrayList<Employee> {

Right now, Employee is a generic type, not the actual class. Since the type is unbound the only thing the compiler can guarantee is that Employee is or (directly / indirectly) extends Object. That's why it shows you that error - Object doesn't have a getName() method.

[Larry Frissell]

Thank you Rob, when I remove the <Employee> from Staff and put ArrayList <Employee> the code works fine.

[Vishal K Prasad]

Removed my reply as already correct reply was posted

[Kevin Workman]

Vishal K Prasad wrote:Can you also check the import for Employee class? May be you two copy of Employee class in your classpath and the one imported here does not have the method. Just a wild guess. Posting the whole code might help.

No. The solution posted was correct and solved the problem. No wild guesses required.

[Wouter Oet]

The term casting an Object is wrong. You can't cast an Object. You can however cast a reference.