JPAstreamer is a lightweight extension for any JPA provider that allows creation of Java Streams from database content.With a single dependency, your application can immediately operate on database elements using standard Stream operators e.g.filter(),sort() andmap().

The following example assumes there is an existing JPA Entity that represents a table containing films as follows:

To operate on the elements of the table, JPAstreamer is first initialized with a simple builder (in this case using a persistence unit named "sakila"):

The obtained streamer is then used to create Streams that are rendered to database queries through JPA. For example:

This will print films rated G in reversed length order (where films of equal length will be in title order) but skipping the first ten and then printing only the following five films.(Film$ is automatically generated from the Film-table Entity at compile-time by JPAstreamer).

In order to minimize the burden on the JVM and the database, JPAstreamer eventually renders the Stream to SQL like so (example from Hibernate/MySQL):

More examples are available in the JPAstreamerdocumentation.

Since JPAstreamer acts merely as an API extension for existing JPA providers it requires minimal installation and configuration efforts. You only need to specify that the JPAstreamer dependency is required to compile your source code.

We gladly welcome any form of contributions, whether it is comments and questions, filed issues or pull requests.

Before we can accept your patches we need to establish a common legal ground to protect your rights to your contributions and the users of JPAstreamer. This is done by signing a Contributor License Agreement (CLA) with Speedment, Inc. The details of this process is laid outhere.

JPAstreamer is released under theLGPL 2.1 License.

Here is a short 1-minute video describing JPAstreamer:

• Install
  • Maven
  • Gradle
  • Resources
• Contributing
• License
• Short Video
• Contents