Search icon CANCEL
Subscription
0
Cart icon
Your Cart (0 item)
Close icon
You have no products in your basket yet
Save more on your purchases! discount-offer-chevron-icon
Savings automatically calculated. No voucher code required.
Arrow left icon
Explore Products
Best Sellers
New Releases
Books
Videos
Audiobooks
Learning Hub
Newsletter Hub
Free Learning
Arrow right icon
timer SALE ENDS IN
0 Days
:
00 Hours
:
00 Minutes
:
00 Seconds
Play Framework essentials
Play Framework essentials

Play Framework essentials: An intuitive guide to creating easy-to-build scalable web applications using the Play framework

Arrow left icon
Profile Icon Julien Richard-Foy
Arrow right icon
$19.99 per month
Full star icon Full star icon Full star icon Half star icon Empty star icon 3.6 (8 Ratings)
Paperback Sep 2014 200 pages 1st Edition
eBook
$17.98 $19.99
Paperback
$32.99
Subscription
Free Trial
Renews at $19.99p/m
Arrow left icon
Profile Icon Julien Richard-Foy
Arrow right icon
$19.99 per month
Full star icon Full star icon Full star icon Half star icon Empty star icon 3.6 (8 Ratings)
Paperback Sep 2014 200 pages 1st Edition
eBook
$17.98 $19.99
Paperback
$32.99
Subscription
Free Trial
Renews at $19.99p/m
eBook
$17.98 $19.99
Paperback
$32.99
Subscription
Free Trial
Renews at $19.99p/m

What do you get with a Packt Subscription?

Free for first 7 days. $19.99 p/m after that. Cancel any time!
Product feature icon Unlimited ad-free access to the largest independent learning library in tech. Access this title and thousands more!
Product feature icon 50+ new titles added per month, including many first-to-market concepts and exclusive early access to books as they are being written.
Product feature icon Innovative learning tools, including AI book assistants, code context explainers, and text-to-speech.
Product feature icon Thousands of reference materials covering every tech concept you need to stay up to date.
Subscribe now
View plans & pricing
Table of content icon View table of contents Preview book icon Preview Book

Play Framework essentials

Chapter 2. Persisting Data and Testing

In this chapter, you will see how you can write executable specifications for your web service and how Play can integrate mainstream data persistence technologies like RDMSes or document stores. More precisely, you will see how to perform the following:

  • Write and run unit tests
  • Simulate HTTP requests and inspect returned HTTP responses
  • Persist data using an RDBMS
  • Use an in-memory database for development

Testing your web service

The architecture of your web service is depicted in the following diagram:

Testing your web service

This section presents the testing libraries that are integrated with Play and the testing infrastructure provided by Play to test the HTTP layer of your web service.

Writing and running tests

As Play projects are just sbt projects by default, you can add tests to your Play project just as you would do for any other sbt project, except that the root directory for test sources is not src/test/scala/ but simply test/.

sbt provides a mechanism to integrate testing libraries so that their tests can be run from the build system. The testing component of Play integrates two testing libraries out of the box: specs2 for Scala tests and JUnit for Java tests. Play projects automatically depend on the Play testing component, so you don't need to add this dependency in your build.sbt file. Obviously, you are free to use any other testing library supported by sbt—just follow their usage instructions...

Persisting data

Obviously, you are free to use any persistence technology such as relational databases, document stores, key-value stores, and graph databases according to your needs. Nevertheless, this section gives insights on the recommended ways to integrate a persistence technology to your Play project.

As the persistence layer is usually independent of the HTTP layer, Play is agnostic to which persistence layer you use. However, most persistence layers need configuration settings, so you need a way to inject these settings to your persistence technology from your application. A common way to achieve this is to define a Play plugin. The next sections show how to integrate a relational database using the provided JDBC and JPA plugins.

Using a relational database

If you are using a relational database, chances are that your database API relies on JDBC. At some point, your database API will need a javax.sql.Connection object to work with and might use JDBC transactions.

Play comes with a...

Using an in-memory database for tests

You now have all the required knowledge to make your web service persistent. Once you have chosen a database technology, select the Play plugins you need (JDBC, JPA, and so on), configure your data sources right from your application.conf file, use the database helper classes provided by the plugins to integrate with your database technology, and finally implement your business layer on top of your database layer.

Once you have made your business layer persistent, you probably want to run your tests to check whether you introduced a regression. However, you will unexpectedly get the following error:

[info] A Shop should
[info] ! add items
[error]    RuntimeException: : There is no started application  (Play.scala:71)

What happened? Remember that your database configuration is read by your Play application at startup and then used by your database layer. The key step is when you retrieve the data source—remember that the method takes an implicit...

Summary

The HTTP layer is made of the routes and controllers.Items components. The business layer is now made of two components, models.Shop and db.Schema (in Java, the latter component is hidden by JPA).

In this chapter, you saw how to write testing specifications for your web service, how to call your actions, supply them with fake HTTP requests, and process their results. You also saw how to integrate with relational database technologies. You learned that you can use the Play singleton to get a reference to the currently running application and, for instance, read its configuration settings. You learned how to hook into your application's life cycle using a global object. Finally, you saw how to start a fake application in your tests.

In the next chapter, you will see how to serve HTML pages and handle forms; your web service will evolve into a web application.

Left arrow icon Right arrow icon

Description

This book targets Java and Scala developers who already have some experience in web development and who want to master Play framework quickly and efficiently. This book assumes you have a good level of knowledge and understanding of efficient Java and Scala code.

What you will learn

  • Set up a unified development environment for both the clientside and serverside code
  • Understand the challenges of building a scalable web application and master the solutions provided by Play framework
  • Integrate the framework with existing clientside or serverside technologies such as persistence systems
  • Harness the reactive programming model to process data streams
  • Design robust, maintainable, and testable code
  • Be proficient in manipulating JSON data blobs
  • Deploy your application on a PaaS platform

Product Details

Country selected
Publication date, Length, Edition, Language, ISBN-13
Publication date : Sep 25, 2014
Length: 200 pages
Edition : 1st
Language : English
ISBN-13 : 9781783982400
Vendor :
Apache
Languages :
Tools :

What do you get with a Packt Subscription?

Free for first 7 days. $19.99 p/m after that. Cancel any time!
Product feature icon Unlimited ad-free access to the largest independent learning library in tech. Access this title and thousands more!
Product feature icon 50+ new titles added per month, including many first-to-market concepts and exclusive early access to books as they are being written.
Product feature icon Innovative learning tools, including AI book assistants, code context explainers, and text-to-speech.
Product feature icon Thousands of reference materials covering every tech concept you need to stay up to date.
Subscribe now
View plans & pricing

Product Details

Publication date : Sep 25, 2014
Length: 200 pages
Edition : 1st
Language : English
ISBN-13 : 9781783982400
Vendor :
Apache
Languages :
Tools :

Packt Subscriptions

See our plans and pricing
Modal Close icon
$19.99 billed monthly
Feature tick icon Unlimited access to Packt's library of 7,000+ practical books and videos
Feature tick icon Constantly refreshed with 50+ new titles a month
Feature tick icon Exclusive Early access to books as they're written
Feature tick icon Solve problems while you work with advanced search and reference features
Feature tick icon Offline reading on the mobile app
Feature tick icon Simple pricing, no contract
$199.99 billed annually
Feature tick icon Unlimited access to Packt's library of 7,000+ practical books and videos
Feature tick icon Constantly refreshed with 50+ new titles a month
Feature tick icon Exclusive Early access to books as they're written
Feature tick icon Solve problems while you work with advanced search and reference features
Feature tick icon Offline reading on the mobile app
Feature tick icon Choose a DRM-free eBook or Video every month to keep
Feature tick icon PLUS own as many other DRM-free eBooks or Videos as you like for just $5 each
Feature tick icon Exclusive print discounts
$279.99 billed in 18 months
Feature tick icon Unlimited access to Packt's library of 7,000+ practical books and videos
Feature tick icon Constantly refreshed with 50+ new titles a month
Feature tick icon Exclusive Early access to books as they're written
Feature tick icon Solve problems while you work with advanced search and reference features
Feature tick icon Offline reading on the mobile app
Feature tick icon Choose a DRM-free eBook or Video every month to keep
Feature tick icon PLUS own as many other DRM-free eBooks or Videos as you like for just $5 each
Feature tick icon Exclusive print discounts

Frequently bought together


Stars icon
Total $ 87.98
Mastering play framework for scala
$54.99
Play Framework essentials
$32.99
Total $ 87.98 Stars icon

Table of Contents

8 Chapters
1. Building a Web Service Chevron down icon Chevron up icon
2. Persisting Data and Testing Chevron down icon Chevron up icon
3. Turning a Web Service into a Web Application Chevron down icon Chevron up icon
4. Integrating with Client-side Technologies Chevron down icon Chevron up icon
5. Reactively Handling Long-running Requests Chevron down icon Chevron up icon
6. Leveraging the Play Stack – Security, Internationalization, Cache, and the HTTP Client Chevron down icon Chevron up icon
7. Scaling Your Codebase and Deploying Your Application Chevron down icon Chevron up icon
Index Chevron down icon Chevron up icon

Customer reviews

Top Reviews
Rating distribution
Full star icon Full star icon Full star icon Half star icon Empty star icon 3.6
(8 Ratings)
5 star 25%
4 star 50%
3 star 0%
2 star 12.5%
1 star 12.5%
Filter icon Filter
Top Reviews

Filter reviews by




Mike Feb 02, 2015
Full star icon Full star icon Full star icon Full star icon Full star icon 5
Excellent book with a lot of examples and tips. Provides a continuous learning form the beginning in a medium technical language which helps understanding everything, even if we are new at PLAY.Recomend it for sure. For deep knowledge the Cookbook is also a mandatory book to summarize, review and learn some new tricks.
Amazon Verified review Amazon
Abhishek Srivastava Jun 24, 2015
Full star icon Full star icon Full star icon Full star icon Full star icon 5
I love this book. I tried couple of play framework books on safari. I found that either they were were old and examples were obsolete or they were very poorly written.Finally I found this book and it is very recent. all examples work. nothing is obsolete.I also find that the book is comprehensive and well written.
Amazon Verified review Amazon
Martin Nov 24, 2014
Full star icon Full star icon Full star icon Full star icon Empty star icon 4
- Concise reading without long stories.- Short code snippets cover just the important parts of solution.- Includes everything important like session authentication, CSRF prevention and others. (I have not found these topics in few other books.)
Amazon Verified review Amazon
Juraj Zachar Jan 01, 2015
Full star icon Full star icon Full star icon Full star icon Empty star icon 4
The content of the book is great but the kindle format is hard to work with. The lack of navigable list of contents makes browsing of the book's chapters cumbersome. I was expecting much better usability and I wish I had gone for a hard cover.
Amazon Verified review Amazon
Dustin Marx Nov 01, 2014
Full star icon Full star icon Full star icon Full star icon Empty star icon 4
"Play Framework Essentials" provides a rapid introduction to the Play Framework. In 7 chapters and under 200 pages, "Play Framework Essentials" introduces Play Framework and covers details such as building and exposing web services with Play, building web application clients that integrate with Play, persisting data from a Play application to a relational database, testing a Play application, refactoring Play application code, and deploying a Play application. The book also describes how developers can take advantage of Play's concurrency model, security support, internationalization support, and caching support."Play Framework Essentials" provides numerous code listings. These are black font on white background with no line numbers and no color syntax. The examples demonstrate applying Play in both Java and Scala programming languages and explains the relatively small number of features that are only available in one language or the other. There are also several graphics in the book that are mostly grayscale but one or two of them has some color in it.Although there are fewer than 200 pages of substantive text in "Play Framework Essentials," the book still manages to cover a significant amount of technical detail. This is accomplished by spending very little time covering historical or background details of the Play Framework and jumping right into technical discussion.
Amazon Verified review Amazon
Get free access to Packt library with over 7500+ books and video courses for 7 days!
Start Free Trial

FAQs

What is included in a Packt subscription? Chevron down icon Chevron up icon

A subscription provides you with full access to view all Packt and licnesed content online, this includes exclusive access to Early Access titles. Depending on the tier chosen you can also earn credits and discounts to use for owning content

How can I cancel my subscription? Chevron down icon Chevron up icon

To cancel your subscription with us simply go to the account page - found in the top right of the page or at https://subscription.packtpub.com/my-account/subscription - From here you will see the ‘cancel subscription’ button in the grey box with your subscription information in.

What are credits? Chevron down icon Chevron up icon

Credits can be earned from reading 40 section of any title within the payment cycle - a month starting from the day of subscription payment. You also earn a Credit every month if you subscribe to our annual or 18 month plans. Credits can be used to buy books DRM free, the same way that you would pay for a book. Your credits can be found in the subscription homepage - subscription.packtpub.com - clicking on ‘the my’ library dropdown and selecting ‘credits’.

What happens if an Early Access Course is cancelled? Chevron down icon Chevron up icon

Projects are rarely cancelled, but sometimes it's unavoidable. If an Early Access course is cancelled or excessively delayed, you can exchange your purchase for another course. For further details, please contact us here.

Where can I send feedback about an Early Access title? Chevron down icon Chevron up icon

If you have any feedback about the product you're reading, or Early Access in general, then please fill out a contact form here and we'll make sure the feedback gets to the right team. 

Can I download the code files for Early Access titles? Chevron down icon Chevron up icon

We try to ensure that all books in Early Access have code available to use, download, and fork on GitHub. This helps us be more agile in the development of the book, and helps keep the often changing code base of new versions and new technologies as up to date as possible. Unfortunately, however, there will be rare cases when it is not possible for us to have downloadable code samples available until publication.

When we publish the book, the code files will also be available to download from the Packt website.

How accurate is the publication date? Chevron down icon Chevron up icon

The publication date is as accurate as we can be at any point in the project. Unfortunately, delays can happen. Often those delays are out of our control, such as changes to the technology code base or delays in the tech release. We do our best to give you an accurate estimate of the publication date at any given time, and as more chapters are delivered, the more accurate the delivery date will become.

How will I know when new chapters are ready? Chevron down icon Chevron up icon

We'll let you know every time there has been an update to a course that you've bought in Early Access. You'll get an email to let you know there has been a new chapter, or a change to a previous chapter. The new chapters are automatically added to your account, so you can also check back there any time you're ready and download or read them online.

I am a Packt subscriber, do I get Early Access? Chevron down icon Chevron up icon

Yes, all Early Access content is fully available through your subscription. You will need to have a paid for or active trial subscription in order to access all titles.

How is Early Access delivered? Chevron down icon Chevron up icon

Early Access is currently only available as a PDF or through our online reader. As we make changes or add new chapters, the files in your Packt account will be updated so you can download them again or view them online immediately.

How do I buy Early Access content? Chevron down icon Chevron up icon

Early Access is a way of us getting our content to you quicker, but the method of buying the Early Access course is still the same. Just find the course you want to buy, go through the check-out steps, and you’ll get a confirmation email from us with information and a link to the relevant Early Access courses.

What is Early Access? Chevron down icon Chevron up icon

Keeping up to date with the latest technology is difficult; new versions, new frameworks, new techniques. This feature gives you a head-start to our content, as it's being created. With Early Access you'll receive each chapter as it's written, and get regular updates throughout the product's development, as well as the final course as soon as it's ready.We created Early Access as a means of giving you the information you need, as soon as it's available. As we go through the process of developing a course, 99% of it can be ready but we can't publish until that last 1% falls in to place. Early Access helps to unlock the potential of our content early, to help you start your learning when you need it most. You not only get access to every chapter as it's delivered, edited, and updated, but you'll also get the finalized, DRM-free product to download in any format you want when it's published. As a member of Packt, you'll also be eligible for our exclusive offers, including a free course every day, and discounts on new and popular titles.