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

Configuring web applications programmatically

In addition to allowing us to configure web applications through annotations and web-fragment.xml, Servlet 3.0 also allows us to configure our web applications programmatically at runtime.

The ServletContext class has new methods to configure servlets, filters, and listeners programmatically. The following example illustrates how to configure a servlet programmatically at runtime, without resorting to the @WebServlet annotation or to XML:

package com.ensode.jakartaeebook.servlet;
//imports omitted
@WebListener()
public class ServletContextListenerImpl implements
  ServletContextListener {
  @Override
  public void contextInitialized(
    ServletContextEvent servletContextEvent) {
    ServletContext servletContext = servletContextEvent.
      getServletContext();
    try {
      ProgrammaticallyConfiguredServlet...