Java Magazine - November/December 2011

//new to java /

Introduction to RESTful
Web Services (Part 2)

Handle the JSON response format with an HTML5 Web client.
MAX BONBHEL

JAVA IN ACTION

PHOTOGRAPH BY ALLEN MCINNIS/GETTY IMAGES

In Part 1 of this three-part series, I showed how to quickly create and deploy a Java Platform, Enterprise Edition (Java EE) application that uses Representational State Transfer (REST) Web services with NetBeans. The application developed in Part 1 will be the basis for this second article on implementing new functionalities.

Now, in Part 2, we will see in detail how to use JavaScript Object Notation (JSON) to handle the response returned to the client. We will also add a small dose of HTML5, JavaScript, and Ajax to call the Web services, store the information locally, and display the information later.

Note: The complete source code for the application designed in this article can be downloaded here.

JSON and HTML5

JSON is a human-readable data
format based on JavaScript tech-
nology. The structure of JSON is
easier to parse and extend than
traditional XML. JSON format is
used by most applications that
provide Web services
through Web clients.

HTML5 is the next generation of HTML. It provides new features that are necessary for modern Web applications. It also standardizes many features of commonly available browser technologies that Web developers have been using for years to create rich Web applications without the need for plug-ins.

HTML5 is designed to be cross-
platform, and it does not require
a specific operating system. The
only thing we need is a modern
Web browser, such as the latest
version of Firefox, Opera, Safari,
or Chrome.

HTML5 provides
very cool
functionalities
for storing the
data in your browser
and accessing
the data with
JavaScript after the
page is loaded.

Let’s Code and Test the JSON
Representation
To begin, we will modify the re-
sources to ensure that the server
returns a response in the format
that we want (JSON).