In this multi-part blog series we will develop a simple JPA-based Java Enterprise application that uses MySQL as its database system. The series walks you through downloading and configuring, programming, deploying, testing the application and finally adding some more advanced features.
- In the second part we will setup the Software Component and Development Components for the enterprise application, add required project facets for JPA persistence, and maintain deployment descriptors for use with the system database.
- In the third part we will program a JPA Entity and a simple Service Façade, which we expose as a Web Service and test in the Web Service Navigator.
- In the fourth part we will move the application from the system database to the MySQL database.
- In the fifth part we will add advanced features to make the application more realistic.
h3. Why MySQL?
MySQL is a popular OpenSource database system. Although it is not among the database systems officially supported by SAP NetWeaver, a search of the SDN forums reveals that in recognition of its wide distribution, the NetWeaver development team tests each release against MySQL.
Using MySQL allows us to play through the process of using any non-system database for developing Java EE applications that use SAP JPA persistence.
h3. Background Info: Is MySQL the same as Adabas or MaxDB?
No, this is a mix-up. There is an RDBMS called Adabas D. In 1997, SAP released their own branch of Adabas D called SAP DB. In 2003, Swedish company MySQL AB was entrusted with the distribution rights for SAP DB, which was renamed to MaxDB, then MaxDB by MySQL. In 2007, it went back to SAP and is still known as MaxDB.
So the MySQL Server is a completely different database system and has very little to do with SAP’s MaxDB database system.
h3. Download and Install MySQL Community Server
Current General Availability release is 5.1. Download the Windows MSI installer (x86) version 5.1.33 from http://dev.mysql.com/downloads/mysql/5.1.html and install it. (I installed it on the Windows XP Professional Server on which my SAP Composition Environment 7.1 EHP 1 runs.)
Choose the default installation options. Write down the password for database user root. We will use it to connect to the database from the server and from NetWeaver Developer Studio. After installation, the database will be up and running.
h3. Download MySQL Connector/J
This is the JDBC driver for MySQL. Download the ZIP file of the current GA release 5.1.7 from http://dev.mysql.com/downloads/#connector-j and uncompress it. It contains archive mysql-connector-java-5.1.7-bin.jar which we will upload to the server and use in NetWeaver Developer Studio to connect to the database.