Book Image

Clojure Programming Cookbook

Book Image

Clojure Programming Cookbook

Overview of this book

When it comes to learning and using a new language you need an effective guide to be by your side when things get rough. For Clojure developers, these recipes have everything you need to take on everything this language offers. This book is divided into three high impact sections. The first section gives you an introduction to live programming and best practices. We show you how to interact with your connections by manipulating, transforming, and merging collections. You’ll learn how to work with macros, protocols, multi-methods, and transducers. We’ll also teach you how to work with languages such as Java, and Scala. The next section deals with intermediate-level content and enhances your Clojure skills, here we’ll teach you concurrency programming with Clojure for high performance. We will provide you with advanced best practices, tips on Clojure programming, and show you how to work with Clojure while developing applications. In the final section you will learn how to test, deploy and analyze websocket behavior when your app is deployed in the cloud. Finally, we will take you through DevOps. Developing with Clojure has never been easier with these recipes by your side!
Table of Contents (16 chapters)
Clojure Programming Cookbook
About the Authors
About the Reviewer

Calling Java methods and accessing Java objects from Clojure

Though the Clojure language looks quite different from Java, Clojure provides full access to Java. This enables Clojure to make use of huge Java assets very efficiently. In general, calling Java assets from Clojure is much simpler and results in less code than calling them from Java. Another big advantage is REPL, which makes programming fun and faster.

Getting ready

In this recipe, we don't use an external library, so the only necessary thing is to start REPL to run code.

How to do it...

We will learn how to instantiate objects, call instance and class methods, access fields and inner classes, and reference classes. Then, we will learn how to manipulate Java arrays.

Instantiating objects

To instantiate an object from a class, use the following syntax:

(ClassName. arg1 arg2 ...) 

For instance, to instantiate a new String object the syntax is as follows:

(String. "abc") 
;;=> "abc" 
(Integer. 1) 
;;=> 1