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 Clojure from Java

In this recipe, we will learn how to define Java classes in Clojure and call them from Java.

Getting ready

To include Java sources in a Leiningen project, we create the project.clj as follows and restart the REPL:

(defproject chapter05 "0.1.0-SNAPSHOT" 
  :description "FIXME: write description" 
  :url "" 
  :license {:name "Eclipse Public License" 
            :url ""} 
  :java-source-paths ["src/java"] 
  :aot [chapter05.calling-from-java] 
  :prep-tasks [ 
               ["compile" "chapter05.calling-from-java"] 
               "javac" "compile" ] 
  :main chapter05.TestHello 
  :dependencies [[org.clojure/clojure "1.8.0"] 

How to do it...

We will take a look at how we define Java classes that can be called from Java.

Defining a simple named class using gen-class

The following code is a very simple code to print string...