NetBeans IDE is free and open source and has a big community of users. You can download the NetBeans IDE from its official website, https://netbeans.org/downloads/.

At the time of writing this book, NetBeans for Java 9 was available only as a nightly build (downloadable from http://bits.netbeans.org/download/trunk/nightly/latest/). As shown in the following screenshot, download all the supported NetBeans bundles as we'll use Javascript too:

GlassFish Server and Apache Tomcat are optional. The required packs and runtimes are denoted as Already Installed (as NetBeans was already installed on my system):

After downloading the installation, execute the installer file. Accept the license agreement as shown in the following screenshot, and follow the rest of the steps to install the NetBeans IDE...

Spring Boot is an obvious choice to develop state-of-the-art production-ready applications specific to Spring. Its website (https://projects.spring.io/spring-boot/) also states its real advantages:

Spring Boot is an amazing Spring tool created by Pivotal and it was released in April 2014 (GA). It was developed based on the request of SPR-9888 (https://jira.spring.io/browse/SPR-9888) with the title Improved support for 'containerless' web application architectures.

You must be wondering...

We will use a simple approach to building a standalone application. It packages everything into a single executable JAR file, driven by a main() method. Along the way, you use Spring's support for embedding the Jetty servlet container as the HTTP runtime, instead of deploying it to an external instance. Therefore, we would create the executable JAR file in place of the war that needs to be deployed on external web servers, which is a part of the rest module. We'll define the domain models in the lib module and API related classes in the rest module.

The following are pom.xml of the lib and rest modules.

The pom.xml file of the lib module:

<?xml version="1.0" encoding="UTF-8"?> 
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation...

Whatever the pom.xml files, whatever we have used until now is enough to execute our sample REST service. This service would package the code into a JAR file. To make this JAR executable we need to opt for the following options:

• Running the Maven tool
• Executing with the Java command

The following sections will cover them in detail.

This method may not work because Java 9, Spring Boot 2, and Spring Framework 5 are all in either in early or snapshot release. In case it does not work, please use a project using Java commands.

Here, we use the Maven tool to execute the generated JAR file, the steps for this are as follows:

1. Right-click on the pom.xml file.
2. Select Run Maven...

This book uses the Postman - REST Client extension for Chrome to test our REST service. I use the 5.0.1 version of Postman. You can use the Postman Chrome application or any other REST Client to test your sample REST application, as shown in the following screenshot:

Let's test our first REST resource once you have the Postman - REST Client installed. We start the Postman - REST Client from either the Start menu or from a shortcut.

Once it's started, you can type the Calculation REST URL for sqrt and value 144 as the path parameter. You can see it in...

In this chapter, you have explored various aspects of setting up a development environment, Maven configuration, Spring Boot configuration, and so on.

You have also learned how to make use of Spring Boot to develop a sample REST service application. We learned how powerful Spring Boot is—it eases development so much that you only have to worry about the actual code, and not about the boilerplate code or configurations that you write. We have also packaged our code into a JAR file with an embedded application container Jetty. It allows it to run and access the web application without worrying about the deployment.

In the next chapter, you will learn the domain-driven design (DDD) using a sample project that can be used across the rest of the chapters. We'll use the sample project online table reservation system (OTRS) to go through various phases of microservices...