Book Image

Learning Play! Framework 2

By : Andy Petrella
Book Image

Learning Play! Framework 2

By: Andy Petrella

Overview of this book

<p>The Learning Play! Framework 2 has been created for web developers that are building web applications. The core idea is to focus on the HTTP features and to enable them through a simplification lens. Building a web application no longer requires a configuration phase, an environment setup, or a long development lifecycle - it's integrated!<br /><br />Learning Play! Framework 2 will enable any web developers to create amazing web applications taking advantage of the coolest features. It's the fastest way to dive into Play!, focusing on the capabilities by using them in a sample application. Although essentially Java based code, a Scala version is presented as well – giving an opportunity to see some Scala in action.<br /><br />After setting up the machine and learning some Scala, you will construct an application which builds from static to dynamic, before introducing a database. <br /><br />Then we'll focus on how data can be consumed and rendered in several ways. This will enable some real time communication through WebSocket and Server-Sent Event – on both server and client sides.</p> <p>The book will end with testing and deployment, which completes any web development project.</p>
Table of Contents (20 chapters)
Learning Play! Framework 2
Credits
About the Author
Acknowledgement
About the Reviewers
www.packtpub.com
Preface
Materials
Index

Body parsing for better reactivity


As noted earlier, the way to manage content in Play! 2 is to use instances of body parsers. In brief, a body parser is a component that is responsible for parsing the body of an HTTP request as a stream to be converted into a predefined structure. This has a common sense ring to it, however their strength is in their way of consuming the stream—in a reactive fashion.

Reactivity, in this context, is meant to describe a process where an application won't block on a task that is actually idle. As a stream consumption task is idle when no bytes are incoming, a body parser should behave the same. It will read and construct an internal representation of the incoming bytes. But it can also decide at any time that it has read enough to terminate and return the representation. On the other hand, if no more bytes are coming into the stream, it can relax its thread in favor of another request; it pauses its work until new bytes are received.

Thinking about an HTTP...