Book Image

Jakarta EE Application Development - Second Edition

By : David R. Heffelfinger
Book Image

Jakarta EE Application Development - Second Edition

By: David R. Heffelfinger

Overview of this book

Jakarta EE stands as a robust standard with multiple implementations, presenting developers with a versatile toolkit for building enterprise applications. However, despite the advantages of enterprise application development, vendor lock-in remains a concern for many developers, limiting flexibility and interoperability across diverse environments. This Jakarta EE application development guide addresses the challenge of vendor lock-in by offering comprehensive coverage of the major Jakarta EE APIs and goes beyond the basics to help you develop applications deployable on any Jakarta EE compliant runtime. This book introduces you to JSON Processing and JSON Binding and shows you how the Model API and the Streaming API are used to process JSON data. You’ll then explore additional Jakarta EE APIs, such as WebSocket and Messaging, for loosely coupled, asynchronous communication and discover ways to secure applications with the Jakarta EE Security API. Finally, you'll learn about Jakarta RESTful web service development and techniques to develop cloud-ready microservices in Jakarta EE. By the end of this book, you'll have developed the skills to craft secure, scalable, and cloud-native microservices that solve modern enterprise challenges.
Table of Contents (18 chapters)
15
Chapter 15: Putting it All Together

Developing WebSocket clientsin JavaScript

Most WebSocket clients are implemented as web pages taking advantage of the JavaScript WebSocket API. We will cover how to do this in the next section.

The Jakarta API for WebSocket provides a client API that allows us to develop WebSocket clients as standalone Java applications. We will be covering this capability later in the chapter.

Developing JavaScript client-side WebSocket code

In this section, we will cover how to develop client-side JavaScript code to interact with the WebSocket endpoint we developed in the previous section.

The client page for our WebSocket example is implemented as a JSF page using HTML5-friendly markup (as explained in Chapter 7).

As illustrated in Figure 9.1, our client page consists of a text area where we can see what the users of our application are saying (it is, after all, a chat application), and a text-input box that we can use to send messages to other users.

Figure 9.1 – Javascript WebSocket client
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