JPA Pitfalls – a Series of Serious JPA Obstacles

Most of our Java-based web-applications store their data in a relational database such as Oracle, PostgreSQL, MySQL, MariaDB or MS SQLServer. The standard way to access and modify the data is using an object-relational mapping as specified by the Java Persistence API (JPA). Over the years JPA has become a mature specification and there are a couple of JPA implementations with strong support such as Hibernate, EclipseLink, OpenJPA and DataNuclues. However, day-to-day project experience demonstrates there are number of pitfalls you might run into when using JPA.

pitfall

To avoid stumbling into the same pitfall again and again, we collected them with their solutions and presented these pairs of problems and solutions. This is a start of a series of blog articles each describing a pitfall and a way to circumvent it.

Continue reading

PostgreSQL: Partitioned tables and Hibernate

The posts PostgreSQL: Partitioning big tables Part 1 and Part 2 describe the implementation of this performance measure from the database view. In an enterprise Java environment often a database is integrated by a JPA framework and closely coupled with the application. This 3rd part about partitioned tables in PostgreSQL shows additions necessary when using Hibernate.

Continue reading

Introducing Hibersap – Part 1: A simple application

This is the first post in a new series about our open source framework Hibersap. You can use Hibersap in your Java applications to implement interfaces to SAP systems. Under the hood, Hibersap uses the SAP Java Connector version 3 or a JCA compatible resource adapter to connect to SAP. It makes use of Java annotations to map Java classes and fields to ABAP function modules and their parameters and offers a Hibernate-like API to remotely execute those function modules.

In this post we will develop a small sample application that shows Hibersap’s basic concepts. The following posts in this series will successively demonstrate other concepts like transactions, data type conversion, using resource adapters or testing Hibersap applications.
Continue reading