learn-jpa-hibernate-swap-in-openjpa

Learn JPA Hibernate

TL;DR Swap In OpenJPA HOW-TO

To use OpenJPA instead of Hibernate:

1. Update pom.xml to exclude hibernate-core and instead include the openjpa dependencies and openjpa-maven-plugin configuration
2. Use the OpenJpaConfiguration class to configure OpenJPA
3. Copy in the OpenJPADialect and OpenJPAVendorAdapter classes into your project
4. Update the spring.jpa.properties in application.yml to properly set up OpenJPA
5. Copy the src/main/resources/META-INF/persistence.xml file into your project
6. Verify via a test case that the configuration works

Notes

OpenJPA does not have a dedicated build for Jakarta EE 9. Instead, "Shade" is used to produce a classified build that is compatible with the new APIs. As such, the pom.xml file has quirky configuration to manage the dependencies. For more information, see this link:

https://rmannibucau.metawerx.net/openjpa-jakarta-tips.html

Also, an Apache Syncope dependency was previously used for OpenJPA vendor support. That dependency had code that was once part of Spring (OpenJPADialect and OpenJPAVendorAdapter). Since that code was not updated to the latest APIs, I copied that code into this project (same license) and made the appropriate Jakarta API change myself.