Description

The JPA Processor shall fill the gap between Olingo V4 and the database if JPA is used for object-relational mapping.

At the current state the JPA Processor provide support for:

1. Generating OData metadata from JPA metadata.
2. Processing Get requests by converting them into Criteria Builder queries.
3. Supporting entity manipulations.

More details can be found in the Tutorials.

Requirements

The JPA Processor requires, others than Olingo, minimum Java version 1.8. The current version comes with Olingo 4.3.0. If later versions of OLingo are available this may change.

Even so no JPA implementation is preferred, as long as it supports JSR-338 Java Persistence 2.1, it has to be stated that all test have been performed with Eclipselink 2.6.2. If you have any isusse with e.g. Hibernate create an issue in github.

Download and Installation

The JPA Processor is a collection of Maven projects. To use it you need to clone the repository, import the projects and declare a dependency to either the metadata generation only:

<dependency>
	<groupId>com.sap.olingo</groupId>
	<artifactId>odata-jpa-metadata</artifactId>
	<version>0.2.4-SNAPSHOT</version>
</dependency>

Or to the complete processor:

<dependency>
	<groupId>com.sap.olingo</groupId>
	<artifactId>odata-jpa-processor</artifactId>
	<version>0.2.4-SNAPSHOT</version>
</dependency>

Limitations

The project is still in the state of incubation, so some incompatible changes my come up, see To-Do. Nevertheless feel free to use the JPA processor where ever it helps.

How to obtain support

For bugs, questions and ideas for enhancement please open an issue in github.

To-Do (upcoming-changes)

The flowing extensions/changes are planned:

• Enable hooks for retrieving data.
• Parallel processing for $expand.
• Enable collection attributes.
• Enable server side paging
• Support of $ref

License

Copyright (c) 2017 SAP SE or an SAP affiliate company. All rights reserved. This file is licensed under the Apache Software License, v.2 except as noted otherwise in the License file.

Release Notes

Version	Changes	Incompatible Changes
0.2.4	- Switch to Olingo version 4.4.0 - Support of Enumeration Types - Support of $count at $expand	Yes
0.2.6	- Solution for issue #21 - JPA Join tables can be used e.g. for Many To Many relationship (issue #22). If such relation shall be used in a filter a corresponding JPA entity is required, which can be hidden from the API using @EdmIgnore. Please be aware that in case both source and target are subtype Eclipselink (version 2.7.1 used) may get confused when generating a subquery for filtering, see Bug 529565	No