Very Good

I don't see that this article credits the book "Head First Design Patterns" The examples are nearly identical. They invented the switch to explain the command pattern.

This Java Tip was published in 1999; Head First Design Patterns came out in 2004.

Athen

how to learn plz help me actully i never remember the thing nd topic.

very very informative and cleared all my doubts. Thank you very much for your effort

Thank you for the article.
It seems though, that with this pattern nobody addresses the values returned from the Execute() method. Just seems strange that someone calls "Add" method and expects no return.

Nice article! It explains everything to make a beginner understand this design pattern.

Accord to Holob, TestCommand.java should only know about the Fan and Light classes. This would be the case, regardless of whether the Command Pattern was being used or not. The Fan is the only thing that needs to know that it has a Switch. Likewise, with the Light. If TestCommand wants to turn on a Light, it sends a message (i.e. invokes a methd on) to the Light, asking it to do that. If the Light use a Switch to turn itself on and off, so be it. TestCommand shouldn't know or care about how the Light turns itself on and off, which means it shouldn't know or care if the Light has a Switch or not. Same with the Fan.

Have gone through so many articles on command pattern, each time I knew something was missing till I chanced upon this one. Absolutely brilliant!! Thank you so much!

pls send pdf formate and examples