Comments on: Multiple Inheritance in Java http://erikras.com/2006/10/23/multiple-inheritance-in-java/ Thoughts and photos from an American living in Spain. Thu, 17 May 2012 04:46:00 +0000 hourly 1 http://wordpress.org/?v=3.3.2 By: Erik R. http://erikras.com/2006/10/23/multiple-inheritance-in-java/#comment-349 Erik R. Tue, 24 Aug 2010 14:04:15 +0000 http://www.erik-rasmussen.com/blog/2006/10/23/multiple-inheritance-in-java/#comment-349 Yes, I know. The language doesn't allow "true MI". However, I've still never seen a more elegant solution to mimicking MI in java. Yes, I know. The language doesn’t allow “true MI”. However, I’ve still never seen a more elegant solution to mimicking MI in java.

]]> By: Daniel Earwicker http://erikras.com/2006/10/23/multiple-inheritance-in-java/#comment-348 Daniel Earwicker Tue, 24 Aug 2010 13:56:59 +0000 http://www.erik-rasmussen.com/blog/2006/10/23/multiple-inheritance-in-java/#comment-348 What you've discovered here is not multiple inheritance. It's multiple calls to some common subroutines in order to avoid code duplication, i.e. ordinary 1970s structured programming. With true MI, there could be an abstract method SelfParenting.getDatabase(). The deriving class would override this to return the database, and the inherited class(es) would be able to call getDatabase() to obtain the database, instead of requiring a parameter to be passed around. What you’ve discovered here is not multiple inheritance. It’s multiple calls to some common subroutines in order to avoid code duplication, i.e. ordinary 1970s structured programming.

With true MI, there could be an abstract method SelfParenting.getDatabase(). The deriving class would override this to return the database, and the inherited class(es) would be able to call getDatabase() to obtain the database, instead of requiring a parameter to be passed around.

]]> By: Erik R. http://erikras.com/2006/10/23/multiple-inheritance-in-java/#comment-347 Erik R. Tue, 04 May 2010 17:51:52 +0000 http://www.erik-rasmussen.com/blog/2006/10/23/multiple-inheritance-in-java/#comment-347 Okay. What does that accomplish? Okay. What does that accomplish?

]]> By: JavaSon http://erikras.com/2006/10/23/multiple-inheritance-in-java/#comment-346 JavaSon Tue, 04 May 2010 17:49:31 +0000 http://www.erik-rasmussen.com/blog/2006/10/23/multiple-inheritance-in-java/#comment-346 How about inheriting from a superclass and having an inner class also inherit from a different superclass. How about inheriting from a superclass and having an inner class also inherit from a different superclass.

]]> By: Michael http://erikras.com/2006/10/23/multiple-inheritance-in-java/#comment-345 Michael Wed, 28 Oct 2009 19:34:53 +0000 http://www.erik-rasmussen.com/blog/2006/10/23/multiple-inheritance-in-java/#comment-345 I can think of a half a dozen occasions I've wished for MI in the past few months. Many of the interface hacks I've had to use instead left a bad taste in my mouth. It's a shame that I know what I WANT to do and are not allowed to. I like this solution. The only complaint I have about it is that it doesn't allow you to inject a different implementation for the interface implementation class. I can think of a half a dozen occasions I’ve wished for MI in the past few months. Many of the interface hacks I’ve had to use instead left a bad taste in my mouth. It’s a shame that I know what I WANT to do and are not allowed to.

I like this solution. The only complaint I have about it is that it doesn’t allow you to inject a different implementation for the interface implementation class.

]]> By: online keno games http://erikras.com/2006/10/23/multiple-inheritance-in-java/#comment-344 online keno games Thu, 19 Mar 2009 07:06:41 +0000 http://www.erik-rasmussen.com/blog/2006/10/23/multiple-inheritance-in-java/#comment-344 The lack of multiple inheritence is a blessing not a curse,and it should be embraced.In a decade of using java <a href="http://www.onlinekenogames.net" rel="nofollow">online keno games</a>I have only one time encountered need for multiple inheritance, and a tiny bit of typing allowed me to use interfaces to eliminate the problem.People should pull out things like the reflection API as a last resort, and should be prepared to resign the next day. The lack of multiple inheritence is a blessing not a curse,and it should be embraced.In a decade of using java online keno gamesI have only one time encountered need for multiple inheritance, and a tiny bit of typing allowed me to use interfaces to eliminate the problem.People should pull out things like the reflection API as a last resort, and should be prepared to resign the next day.

]]> By: erik http://erikras.com/2006/10/23/multiple-inheritance-in-java/#comment-343 erik Mon, 21 May 2007 20:12:01 +0000 http://www.erik-rasmussen.com/blog/2006/10/23/multiple-inheritance-in-java/#comment-343 An "Add-In" for an IDE? Which IDE? Anyway, I look forward to seeing what you come up with. An “Add-In” for an IDE? Which IDE?

Anyway, I look forward to seeing what you come up with.

]]> By: johanatan http://erikras.com/2006/10/23/multiple-inheritance-in-java/#comment-342 johanatan Mon, 21 May 2007 19:53:28 +0000 http://www.erik-rasmussen.com/blog/2006/10/23/multiple-inheritance-in-java/#comment-342 P.S. I wouldn't call this a 'flaw' either. It's more of a deficiency. But, I'm currently working on the Add-In that I hoped would fill in the gap. I'll post a link to it when it's done. P.S. I wouldn’t call this a ‘flaw’ either. It’s more of a deficiency. But, I’m currently working on the Add-In that I hoped would fill in the gap. I’ll post a link to it when it’s done.

]]> By: johanatan http://erikras.com/2006/10/23/multiple-inheritance-in-java/#comment-341 johanatan Thu, 19 Apr 2007 19:49:08 +0000 http://www.erik-rasmussen.com/blog/2006/10/23/multiple-inheritance-in-java/#comment-341 I'm not a dogmatic C++ programmer, but I do enjoy having the option to use multiple inheritance. It saves you from having to 'wrap' all your method calls to the inner static. And, also you aren't limited to using a static (i.e., your example could have had and used members in the interface). Of course, multiple inheritance can be abused, but 'with great power comes great responsibility'. It would be really nice if there was a wrapper generator (i.e. macro) in the IDE for this sort of multiple inheritance workaround (or for the containment approach). I’m not a dogmatic C++ programmer, but I do enjoy having the option to use multiple inheritance. It saves you from having to ‘wrap’ all your method calls to the inner static. And, also you aren’t limited to using a static (i.e., your example could have had and used members in the interface). Of course, multiple inheritance can be abused, but ‘with great power comes great responsibility’.

It would be really nice if there was a wrapper generator (i.e. macro) in the IDE for this sort of multiple inheritance workaround (or for the containment approach).

]]>