java

All posts tagged java

How Java 8 Streams Work

Posted by Jacob Zimmerman on 2015-12-19
Posted in: Functional Programming, Java. Tagged: , , , , , , , , , , . 6 Comments

When I first laid eyes on Java 8’s Stream API and found out that it worked lazily (then found out what that meant), I was blown away and utterly baffled. It didn’t seem possible at all. Eventually, I was able to wrap my head around it, realizing it was done with my favorite design pattern: the Decorator Pattern!

In this post, I’m going to go through and write up a simplified implementation, only going through the filter(), map(), and reduce() methods. We’ll also be ignoring the ability to parallelize the calls. Lastly, for the sake of readability, I’ll be ignoring super and extends in the generics. Continue Reading

Flag Parameters and Overloading in Python, Java, and Kotlin

Posted by Jacob Zimmerman on 2015-08-15
Posted in: General Practices, Java, Kotlin, Python. Tagged: , , , , , , , . 4 Comments

Jumping around between multiple languages can help you notice some differences between idioms and best practices in different languages. One of the more interesting differences has to do with one function doing multiple things. Continue Reading

Replacing Inheritance with Composition

Posted by Jacob Zimmerman on 2015-05-09
Posted in: Design Patterns, General Practices, Java, Kotlin, Refactoring. Tagged: , , , , , , , . 4 Comments

Quite a while back, I posted about how, despite the fact that you should prefer composition over inheritance, you can best design classes for inheritance. Now, I wish to give some examples of how you can take your code that uses inheritance and change it to use composition instead, which will often actually make your code more flexible.

The code will be in java, but the concepts can transferred to any language that is object-oriented. Some languages might have constructs that make parts of this easier, too (Kotlin’s Delegates).

One thing is important to remember, though: Even if you switch “completely” to composition, you will still have some inheritance. This inheritance will be from interfaces and interface-like classes only, though. It barely counts as inheritance, really, since all it’s doing is restricting itself to an API and not inheriting implementation details. Continue Reading

Reblog: The Decorator Pattern with Java 8

Posted by Jacob Zimmerman on 2015-04-16
Posted in: Design Patterns, Functional Programming, Java, Reblog. Tagged: , , , , . Leave a comment

I love the decorator pattern. It’s the epitome of composition over inheritance and the greatness that can come from it. It also has potential for fluent APIs. In the following article, the writer presents a generic decorating method that I really like, for times when you may extend the list of decorators in the future and you don’t want to add additional methods for them.
Check it out!
http://blog.codefx.org/design/patterns/decorator-pattern-java-8/