Overview

This is a learning project; it's purpose be used as a starting point for a RESTful web service implemented with Spring 3.1 and Java configuration and to provide solutions to the common requirements necessary to properly implement REST

Technology Stack

The project uses the following technologies:

• web/REST: Spring 3.1
  
• marshalling: Jackson (for JSON) and XStream (for XML)
  
• persistence: JPA, Spring Data JPA and Hibernate
  
• testing: Junit, Hamcrest, Mockito, rest-assured
  

THE PERSISTENCE LAYER (technical notes)

The DAO layer

• to create a new DAO, only the interface needs to be created; Spring Data JPA will generates the DAO implementation automatically
• the DAO interface MUST extend the Spring Data managed interface: JpaRepository (with the correct parametrization)
• the DAO layer is aware of the persistence engine it uses; this information MUST be encoded in the name; for example: IPrincipalJpaDAO for JPA instead of just IPrincipalDAO

The Service layer

• all Service interfaces MUST extend the IService interface (with the proper parametrization)

• all Service implementations MUST extend the AbstractService abstract class (with the proper parametrization)

• extending AbstractService and IService enables a base of consistent and common functionality across services

• the Service artifacts MUST be annotated with the @Service annotation

• the Service layer is not aware of the persistence engine it uses (indirectly); if the persistence engine will change, the DAO artifacts will change, and the service will not

THE WEB LAYER (technical notes)

The Controller layer

• the Controller layer MUST only use the Service layer directly (never the DAO layer)
• the Controller layer SHOULD not implement any interface
• the Controller layer MUST extend AbstractController (with the proper parametrization)
• the Controller artifacts MUST be annotated with the @Controller annotation

Transaction Management and Configuration (technical notes)

• the Service layer is the transaction owner (and is annotated with @Transactional)
• the default transaction semantics are: propagation REQUIRED, default isolation, rollback on runtime exceptions
• NOTE: the transactional semantics MAY be subject to change

Eclipse

• see the Eclipse wiki page of this project

A Learning Project

Because it's a learning project, most of it's implementation is explained carefully and in great detail, in a series of posts:

Spring and Maven basics

• Java based Spring Configuration
  
• Usage of new concepts introduced with Spring 3.1
  
• How to set up Integration Testing with the Maven Cargo plugin

Web Tier (REST)

• Spring MVC for the REST web service
  
• Driving API discoverability with integration test
  
• Implementation of Discoverability with Spring
  
• REST advanced content type negotiation
  

Security

• Security of the REST web service with Spring Security 3.1
  
• Basic and Digest authentication for the same URI mapping of the RESTful service
  

Persistence

• The Persistence Layer with Spring 3.1 and Hibernate
  
• The Persistence Layer with Spring 3.1 and JPA
  
• Simplifying the Data Access Layer with Spring and Java Generics
  

Testing

• Integration testing of the REST service
  
• Comprehensive unit testing of the web tier, focusing on relevant behaviors to avoid brittleness