Confusion with Object class

Question

We all know that all classes implements Object directly or indirectly. That is why we get all public methods available in Object class.
But as the definition says, if our class extends Object class indirectly and we are able to get public methods like notify(), notifyAll() etc why are we unable to get the protected method clone() of this class even our class extends Object class??
I mean to say either both type of methods must not be available or must be available.
Hope I am clear about my issue??
Can any of you guys explain it???
Regards.

Answer 1

Your class needs to implement Cloneable interface.
For example this will throw an exception -
public class TestClone {
          void foo() throws Exception {
          clone();
          public static void main(String args[]){
               try {
                    new TestClone().foo();
               }catch (Exception ex){
                    ex.printStackTrace();
This will not -
public class TestClone implements Cloneable{
          void foo() throws Exception {
          clone();
          public static void main(String args[]){
               try {
                    new TestClone().foo();
               }catch (Exception ex){
                    ex.printStackTrace();
}