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Re: generic extends problem

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On 2014-07-08 12:22:29 +0000, Eric Sosman said:

> On 7/8/2014 2:24 AM, Philipp Kraus wrote:
>> Hello,
>> 
>> I have got a complex class structure, the signature of the class is:
>> 
>> public abstract class IMultiLayer<T extends IStepable & Painter> extends
>> CompoundPainter<T> implements IQueue<T>, IViewableLayer, IDataLayer,
>> IVoidStepable, ILayer
>> 
>> The interfaces are defined like
>> 
>> interface IDataLayer;
>> interface IStepable;
>> interface IViewableLayer;
>> 
>> interface IVoidStepable extends IStepable;
>> interface IReturnStepable extends IStepable;
>> interface ILayer extends IStepable;
>> interface IQueue<T> extends Queue<T>
>> 
>> 
>> I create classes with
>> 
>> public class myContent implements IStepable, Painter
>> 
>> public class myLayer extends IMultiLayer<myContent>
>> 
>> I can compile the structure with Java 1.8, but I get an
>> ClassCastException. I have defined a Map
>> with
>> 
>> Map<String, ILayer> x = new Map();
>> x.put( "test", new myLayer )
>> (myLayer) x.get("test"); // the exception is raised on the cast
>> 
>> The message text of the exception is: cannot be cast to IStepable.
>> I don't understand way the exception is thrown, because the class
>> implements the correct interface.
>> If I swap T extends IStepable & Painter to T extends Painter &
>> IStepable, I get the same exception with
>> cannot be cast to Painter
>> 
>> I'm a little bite clueless and need a hint to solve the problem
> 
>      Could you post some actual code, instead of paraphrasing?
> What you've shown cannot possibly be what you're actually running
> ("new Map()", "new myLayer" with no parens, ...)
> 
>      See <http://sscce.org/>.

Sorry for the late answer, but the structure was quite right, but my 
cached Java classes
are exists in an older version. I habe removed the cache and recompile 
the whole project
and everything works fine

Phil

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generic extends problem Philipp Kraus <philipp.kraus@flashpixx.de> - 2014-07-08 08:24 +0200
  Re: generic extends problem Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-07-08 08:22 -0400
    Re: generic extends problem Philipp Kraus <philipp.kraus@flashpixx.de> - 2014-07-22 14:54 +0200

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