HATEOAS using Spring Framework

HATEOAS is a constraint of the REST application architecture which is very often ignored by developers. In many cases this is caused by the lack of support of frameworks used to build and expose RESTful services. In this post I will show how quickly we can add HATEOAS to RESTful web services using Spring Framework. Source code of the demo web application presented below are available for download, run it using mvn tomcat7:run command. Also you can read a nice presentation about why HATEOAS is important.

The Spring HATEOAS Library (currently in Release 0.6) provides API to help creating REST representations that follow the HATEOAS principle. The core problem it tries to address is link creation and representation assembly. Let's see the main steps required for enabling the HATEOAS for a RESTful web service:

CRUD RESTful services using Spring Framework

In this post I will show how to build CRUD (Create, Read, Update, Delete) REST-ful (Representational State Transfer) services using Spring Framework. Spring Framework version used in this example is 3.0.6.RELEASE. Apache Tomcat version used for testing the web services is 6.0.29 (default Tomcat version used by Tomcat Maven Plugin of Apache Maven 2.2.1). Project sources are available for download. So let’s start, step by step:

1. First we have to define the resource on which the CRUD operation will be performed and how this resource will be represented. In our example we will use a resource that represents a User. The resource will be represented using XML (Extensible Markup Language). At the end of the post I will show how you can switch the resource representation to JSON (JavaScript Object Notation) or any other supported form.
2. Create a Maven project. We will use Maven for project management and build. Maven POM is shown below: