RESTful Java Web Services

Jose Sandoval

• Publisher: Packt Publishing
• Year: 2009
• eBook ISBN: 9781847196460
• Edition: 1
• Topic: Computer Science
• Subtopic: Information Technology
• Index: Computer Science

In Detail

If you are already familiar with REST theory but are new to RESTful Java web services, and want to use the Java technology stack together with Java RESTful frameworks to create robust web services, this is the book for you.

This book is a guide to developing RESTful web services using Java and the most popular RESTful frameworks available today. It covers the theory of REST; practical coding examples for RESTful clients; a practical outline of the RESTful design process-yes, it's different from traditional web application development; and a complete implementation of a non-trivial web service using the following frameworks: Jersey's JAX-RS, Restlet's Lightweight REST, JBoss's JAX-RS RESTEasy, and Struts 2 with the REST plug-in.

We begin with an introduction to REST theory, for example, what it means for a web service to be RESTful, what it means for a web service to exchange representations of resources, and what it means to only use the conventional HTTP request method types-GET, POST, PUT, DELETE-for client/server communication. Before moving into the design and implementation process of a non-trivial web service, we look at a set of sample Java applications that connect to existing REST services that are freely available (Google, Yahoo, Twitter). We then outline a practical design process for RESTful web services and then cover the four most widely used frameworks available to date: JAX-RS implementations such as Jersey and RESTEasy, the Restlet framework, and Struts 2 with the REST plug-in. We cover each framework in detail to allow you to compare the strengths and weaknesses of each framework and to begin developing your own web services after the first reading; what's more, the whole source is included for you to modify and deploy in your own web services. Finally, we discuss the most common performance issues faced by RESTful web services and cover practical solutions to security-related issues such as authentication and data transfer.

A JAVA web developer's guide for building powerful and flexible RESTful web services

Approach

The approach we take is ideal for software developers with some, or extensive, programming experience: we design a RESTful API, which serves as our software specification, and implement it with every framework discussed in the book-there are no hypothetical examples; only practical working applications.

Who this book is for

This book is for Java developers who want to code RESTful web services using any of the open source RESTful frameworks available to date, for example, JAX-RS implementations such as Jersey and RESTEasy, the Restlet lightweight framework, or Struts 2 with the REST plug-in.

You don't need to know REST, as we cover the theory of REST and web services; however, you should be familiar with the Java language and have some understanding of Java web applications.

For each framework, we develop the same web service outlined in Chapter 4, so there is lots of working code available. This is a practical guide and the majority of the book is about coding RESTful web services, and not just about the theory of REST.

RESTful Java Web Services

Jose Sandoval

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Table of Contents

RESTful Java Web Services

Credits

About the Author

About the Reviewers

Preface

What this book covers

What you need for this book

Who this book is for

Conventions

Reader feedback

Customer support

Errata

Piracy

Questions

1. RESTful Architectures

What is REST?

Resources

Representation

URI

Uniform interfaces through HTTP requests

GET/RETRIEVE

POST/CREATE

PUT/UPDATE

DELETE/DELETE

Web services and the big picture

Summary

2. Accessing RESTful Services — Part 1

Getting the tools

RESTful clients

Java command-line application

Jakarta Commons HTTP Client

Java desktop application

JSP application

Servlet application

Summary

3. Accessing RESTful Services — Part 2

Getting the tools

Semantic search mashup

Application architecture

Web application definition

User interface layer

Parsing JSON structures

Servlet layer

SemanticHacker parser Servlet

Google search Servlet

Twitter search Servlet

Yahoo search Servlet

Yahoo image search Servlet

Compiling and running the application

Summary

4. RESTful Web Services Design

Designing a RESTful web service

Requirements of sample web service

Resource identification

Representation definition

XML representations

Users

Messages

JSON representations

Users

Messages

URI definition

Executing logic with RESTful URIs

Using URIs to request representation types

Summary

5. Jersey: JAX-RS

Getting the tools

JAX-RS

Jersey the JAX-RS 1.1 reference implementation

Annotations

Jersey resource

URIs

@Path

HTTP methods

@GET

@POST

@PUT

@DELETE

Relative paths in methods

URI variables

@PathParam

Input and output formats

@Consumes

@Produces

Parameters

@FormParam

Web service architecture

Persistence layer

RESTful web service implementation with Jersey

Application deployment

URI and resources

/users

HTTP GET

XML representation

JSON representation

HTTP POST

/users/{username}

HTTP GET

XML representation

JSON representation

HTTP PUT

HTTP DELETE

/messages

HTTP GET

XML representation

JSON representation

HTTP POST

/messages/{messageID}

HTTP GET

XML representation

JSON representation

HTTP DELETE

/messages/users/{username}

HTTP GET

XML representation

JSON representation

/messages/search/{search_item}

HTTP GET

XML representation

JSON representation

Using this RESTful web service

Summary

6. The Restlet Framework

Getting the tools

Restlet

Restlet 1.1

Restlet application and URI mappings

Handling HTTP requests

HTTP GET and content negotiation (HTTP Accept header)

Content negotiation and the HTTP Accept header

HTTP POST

HTTP PUT

HTTP DELETE

Implementation using Restlet 1.1

Restlet application and URI mappings

URIs and resources

/users

HTTP GET

HTTP POST

/users/{username}

HTTP GET

HTTP PUT

HTTP DELETE

/messages

/messages/{messageID}

/messages/users/{username}

/messages/search/{search_item}

Restlet 2.0

Restlet application and URI mappings

Annotations

@Get and content negotiation (HTTP Accept header)

@Post

@Put

@Delete

Implementation using Restlet 2.0

Restlet application and URI mappings

URIs and resources

/users

HTTP GET

XML representation

JSON representation

HTTP POST

/users/{username}

HTTP GET

XML representation

JSON representation

HTTP PUT

HTTP DELETE

/messages

/messages/{messageID}

/messages/users/{username}

HTTP GET

/messages/search/{search_item}

HTTP GET

Summary

7. RESTEasy: JAX-RS

Getting the tools

RESTEasy — a JAX-RS implementation

Web service architecture

RESTful web service implementation with RESTEasy

Application deployment

URI and resources

/users

/users/{username}

/messages

/messages/{messageID}

/messages/users/{username}

/messages/search/{search_item}

Summary

8. Struts 2 and the REST Plugin

Getting the tools

Struts 2

REST plugin

URI mappings

HTTP request handlers

Web service architecture

RESTful web service implementation with Struts 2

Application deployment

URIs and resources

/users and /users/{username}

HTTP GET /users

HTTP GET /users/{username}

HTTP POST /users

HTTP PUT /users/{username}

HTTP DELETE /users/{username}

/messages and /messages/{messageID}

/usermessages/{username}

/searchmessages/{search_item}

Summary

9. Restlet Clients and Servers

Getting the tools

Restlet standalone applications

Restlet clients

HTTP GET requests

HTTP POST requests

HTTP PUT requests

HTTP DELETE requests

Restlet servers

Summary

10. Security and Performance

Security

Securing web services

Custom token authentication

HTTP basic authentication

Clients and basic authentication

Servers and basic authentication

Single username and password

Tomcat realms

OAuth — accessing web services on behalf of users

Performance

High availability

Scalability

On-demand infrastructures

Performance recommendations

Summary

Index

RESTful Java Web Services

Copyright © 2009 Packt Publishing

All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, without the prior written permission of the publisher, except in the case of brief quotations embedded in critical articles or reviews.

Every effort has been made in the preparation of this book to ensure the accuracy of the information presented. However, the information contained in this book is sold without warranty, either express or implied. Neither the author, nor Packt Publishing, and its dealers and distributors will be held liable for any damages caused or alleged to be caused directly or indirectly by this book.

Packt Publishing has endeavored to provide trademark information about all of the companies and products mentioned in this book by the appropriate use of capitals. However, Packt Publishing cannot guarantee the accuracy of this information.

First published: November 2009

Production Reference: 1051109

Published by Packt Publishing Ltd.

32 Lincoln Road

Olton

Birmingham, B27 6PA, UK

ISBN 978-1-847196-46-0

www.packtpub.com

Cover Image by Duraid Fatouhi (<[email protected]>)

Credits

Author

Jose Sandoval

Reviewers

Atanas Roussev

Richard Wallace

Acquisition Editor

Sarah Cullington

Development Editor

Dhiraj Chandiramani

Technical Editor

Ishita Dhabalia

Copy Editor

Sanchari Mukherjee

Indexer

Rekha Nair

Editorial Team Leader

Gagandeep Singh

Project Team Leader

Lata Basantani

Project Coordinator

Srimoyee Ghoshal

Proofreader

Lynda Silwoski

Graphics

Nilesh R. Mohite

Production Coordinator

Dolly Dasilva

Cover Work

Dolly Dasilva

About the Author

Jose Sandoval is a software developer based in Canada. He has played and worked with web technologies since the Mosaic web browser days. For the last 12 years he's worked or consulted for various financial institutions and software companies in North America, concentrating on large-scale Java web applications. He holds a Bachelor...

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• RESTful Java Web Services