JEST: REST on OpenJPA

JEST is a REST style access to any OpenJPA runtime.

The salient principles of JEST are:

• non-invasive : Any persistent data managed by OpenJPA can be accessed without any change to POJO classes or to an existing application.
• language-neutral : A client not necessarily Java-based can access persistent data simply by sending an HTTP request. JEST is URI-based as opposed to API-based.
• schema-free : The content and format of the response is controlled by the client.

In REST (Representational State Transfer) terminology,

• the resources are customizable graph of persistent objects.
• the representation of resources are in XML or specialized JSON. JSON is specialized to account for any circular reference in the object graph. However, the JSON representation is consumable by other standard JSON parser.
• the life time of any computational resources used by JEST is bound by a single HTTP request-response lifetime.

Any client can send a HTTP request to a OpenJPA based application

is a foundational concept in the architecture for World Wide Web. JEST promotes REST style interaction between a client and an application based on OpenJPA. JEST can be deployed in as a servlet for a web application using OpenJPA as a persistence provider. can send HTTP requests and receive persistent data as response in JSON, XML or other string based format.

JEST is described under the following sections

• Using JEST
• URI Syntax of client-server communication
• Representation of persistent state
• Transaction semantics