Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.java.programmer > #39713

Re: how to add a method specific to builder of specific type only

Show all headers | View raw

On 11/26/2021 9:15 AM, mike wrote:
> 
> I want to add a method that is specific to DeleteSubtreeBuilder .
> 
> SubtreeBuilders.createDeleteSubtree().appendOperation(OperType.DELETE)
> 
> I just cannot seem to be able to add:
> 
> appendOperation(OperType type) so it only appears in the DeteleSubtreeBuilder that SubtreeBuilders.createDeleteSubtree() returns.

     Since createDeleteSubtree() returns a SubtreeBuilder reference, the
only methods callable through that reference are those belonging to (or
inherited by) the SubtreeBuilder class.  Even if the actual instance
returned happens to be a subclass with additional methods, you cannot
use a SubtreeBuilder reference to call them.

     I'm not entirely sure what to suggest, since I'm not entirely sure
I understand what you're trying to do.  One likely possibility, though,
is to change createDeleteSubtree() to return a DeleteSubtreeBuilder
instead of a "vanilla" SubtreeBuilder (assuming DeleteSubtreeBuilder
is a subclass of SubtreeBuilder, which isn't actually spelled out in
the code provided).  If the class relationships aren't as I assume, I'm
afraid I don't know how to help.

> public final class SubtreeBuilders {
>   
>      public static SubtreeBuilder<DeleteSubtree> createDeleteSubtree() {
>          return new DeleteSubtreeBuilder();
>      }
> 
>    
>      public static SubtreeBuilder<SetSubtree> createSetSubtree() {
>          return new SetSubtreeBuilder();
>      }
> 
> static class DeleteSubtreeBuilder extends AbstractSubtreeBuilder<DeleteSubtree>{

     (I'm guessing AbstractSubtreeBuilder is a subclass of SubtreeBuilder
or implements a SubtreeBuilder interface, but I can't be sure.)

>      	
>          @Override
>          protected DeleteSubtree internalBuild() {
>              return new DeleteSubtreeImpl(this);
>          }
> 		
>      }
> 
> }

-- 
esosman@comcast-dot-net.invalid
Look on my code, ye Hackers, and guffaw!

Back to comp.lang.java.programmer | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

how to add a method specific to builder of specific type only mike <mikaelpetterson@hotmail.com> - 2021-11-26 06:15 -0800
  Re: how to add a method specific to builder of specific type only Eric Sosman <esosman@comcast-dot-net.invalid> - 2021-11-26 13:09 -0500
  Re: how to add a method specific to builder of specific type only Arne Vajhøj <arne@vajhoej.dk> - 2021-11-26 19:13 -0500

csiph-web