Cloneable questions

[Guest]

I want to clone a Vector WITH its elements. If any of its elements is
not Cloneable I want to return the element itself.
So the code is this:

--------------------
Vector v = .......;

Vector new_vector = new Vector();
for (int z = 0; z < v.size(); z++) {
Object o = v.elementAt(z);
if (o instanceof Cloneable)
o = ((Cloneable) o).clone(); // compile error
new_vector.add(o);
}

 

[Guest]

I want to clone a Vector WITH its elements. If any of its elements is

not Cloneable I want to return the element itself.
So the code is this:

--------------------
Vector v = .......;

Vector new_vector = new Vector();
for (int z = 0; z < v.size(); z++) {
Object o = v.elementAt(z);
if (o instanceof Cloneable)
o = ((Cloneable) o).clone(); // compile error
new_vector.add(o);
}
--------------------

Why I have compile error?
Is there a way to clone a Cloneable object upcasted to Object?
Or I must create an Interface Cloneable2 which refers to clone(); as
public?

Its to easy for my Objects:

public interface Clone {
public Object clone();
}

but for other Cloneable Objects?

 

[Fred]

It rarely hurts to post the compiler error when asking why something
won't compile.

 

[Thomas Bühler]

Hi
The Cloneable Interface itself doesn't define a clone() Method.
So you can't cast to Cloneable and call the clone() Method.
You have to define your own Clone Interface which define a clone() Method or
call the default clone via reflection call.

e.g.

public static Object cloneCallReflect(Object o) {
Method m = null;
if (o instanceof Cloneable) {
try {
m = o.getClass().getMethod("clone", (Class [])null);
return m.invoke(o, (Object[])null);
} catch (Exception e) {
e.printStackTrace();
}
}
// returns the original.
return o;
}

Best regards
Thomas Buehler