Just learned about HEDL, the Hibernate Entity Definition Language. It’s yet another DSL to ease the pain of working with JPA/Hibernate. I really feel the need to talk what’s so fundamentally wrong with HEDL and, to a lesser extent, with Hibernate’s own meta model generator. I’d like to show why Querydsl, particularly when used in […]
While debugging a Spring/Hibernate-based web application I found this in the logs. Pre-bound JDBC Connection found! HibernateTransactionManager does not support running within DataSourceTransactionManager if told to manage the DataSource itself. It is recommended to use a single HibernateTransactionManager for all transactions on a single DataSource, no matter whether Hibernate or JDBC access. Sounds as something […]
JPA batch inserts (aka bulk inserts) may seem trivial at first. However, if you’re not careful you won’t see the performance gains you expect even though your application works “just fine”. If you follow the below guidelines your JPA batch inserts should be blazingly fast, though. JPA batch inserts with Hibernate All the material presented […]
Here’s a pretty neat approach to add AccessDescisionVoters to the default AccessDescisionManager in Spring Security: /** * This BeanPostProcessor adds all {@link AccessDecisionVoter}s that are set with * {@link #setAdditionalAccessDecisionVoters(List)} to beans that are instances of {@link AffirmativeBased}. This is the * default {@link AccessDecisionManager} implementation that the spring security namespace handler creates. * <p> […]
In order to test a particular feature of our JEE application I installed a free copy of MS SQL Server 2012 Express. I’m a total MS SQL illiterate. As always with MS SQL I used the jTDS JDBC driver to connect from Java. The first hurdle was to learn that MS SQL Express by default […]
final Image image = …; final ByteArrayOutputStream baos = new ByteArrayOutputStream(); try { final BufferedImage bufferedImage = createBufferedImageFrom(image); ImageIO.write(bufferedImage, “png”, baos); } finally { IOUtils.closeQuietly(baos); } return baos.toByteArray(); private BufferedImage createBufferedImageFrom(final Image image) { if (image instanceof BufferedImage) { return (BufferedImage) image; } else { final BufferedImage bi = new BufferedImage(image.getWidth(null), image.getHeight(null), BufferedImage.TYPE_INT_RGB); final Graphics2D […]
If your application sends SMS you want to make sure that characters to be sent comply with GSM 03.38 (e.g. 7bit). If you need to validate (user) input for invalid characters you could do that pretty easily with regular expressions. For Java the following regex is ready to use. For other languages you can base […]
dnsjava to resolve whatever address request.getRemoteAddr() would return. This worked very well in most cases. However, in some cases I would see something like: [quote]java.net.UnknownHostException: Invalid address: fe80::1d9:b65a:ed86:7940%11[/quote] Not being much of a networking expert I was puzzled about the ‘%11’. Once again superuser.com came to rescue: http://superuser.com/questions/99746/why-is-there-a-in-the-ipv6-address
At the technical panel discucssion on Friday morning at Devoxx there was the interesting question “Does Oracle’s corporate culture stand in the way of success for Java?”. Even more interesting was the answer from either Brian Goetz or Mark Reinold (don’t remember), both big wigs at Oracle… “I think Java became a success despite Sun’s […]
The two keynotes at Devoxx 2011 yesterday by Henrik Ståhl and Cameron Purdy from Oracle and today by Google’s Tim Bray couldn’t have been more different. If that is all Oracle’s got to bring to the table then I fear they’re in big trouble… While Henrik Ståhl showed at least some passion and inspiration (neatly […]