Book Image

Play Framework Cookbook - Second Edition

By : Alexander Reelsen, Giancarlo Inductivo
Book Image

Play Framework Cookbook - Second Edition

By: Alexander Reelsen, Giancarlo Inductivo

Overview of this book

<p>As web and mobile systems become more sophisticated, anchoring systems in a mature, solid framework has become increasingly important. Play 2 provides developers with the necessary tools to build robust web applications.</p> <p>This book is a compilation of useful recipes aimed at helping developers discover the power of Play 2. The introductory section serves as a primer to Play Framework, wherein all the fundamentals of the framework are covered extensively. It then explains the usage of controllers and how modules can be leveraged for optimal performance. Next, the book walks you through creating and using APIs, followed by extensive real-world applications. Finally, you will learn to manage applications post production.</p>
Table of Contents (15 chapters)
Play Framework Cookbook Second Edition
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Using filters


For this recipe, we will explore how Play Framework provide APIs for HTTP request and response filters. HTTP filters provide a way to transparently decorate a HTTP request or response and is useful for lower-level services (such as response compression), gathering metrics, and more in-depth logging.

Note

It is also worth noting that presently (as of Play 2.3.7), HTTP filters are best implemented using the Play Scala API with the play.api.mvc.EssentialFilter trait. So for this recipe, we will implement a Scala-based filter for our Java recipe.

How to do it…

For Java, we need to take the following steps:

  1. Run the foo_java application with Hot-Reloading enabled.

  2. Create a new filter object by creating the file foo_java/app/ResponseTimeLogFilter.scala, and adding the following contents:

      import play.api.mvc._
    
      object ResponseTimeLogFilter {
          def apply(): ResponseTimeLogFilter = {
             new ResponseTimeLogFilter()
           }
         }
    
      class ResponseTimeLogFilter extends Filter ...