Why is #clone() not in the Cloneable interface?

Question

I was reading up on performing a deep-copy of an array correctly, however I was confused about how the #clone() is implemented. It is a member of the java.lan

Answer 1

clone() method is unnecessary, every object could invoke Object.clone method by reflect, so an object can be cloned depends on whether to implement Cloneable interface. This is for a security reason. You can simply clone an object which implements Cloneable by this util:

@SuppressWarnings("unchecked")
public static  T clone(Cloneable obj) {
    T rtn = null;
    try {
        Method method = Object.class.getDeclaredMethod("clone");
        method.setAccessible(true);
        rtn = (T) method.invoke(obj);
    } catch (Throwable t) {
        t.printStackTrace();
    }
    return rtn;
}