2007 Predictions

Everybody doing it! Not wanting to be left in the cold, I will follow the herd and make predictions for 2007.

RoR will run flawlessly on a Java Application Server

The good people from JRuby are making incredible progress since they've been hired by Sun. We will soon be able to run RoR applications with no (or very little and trivial) modifications on Glassfish or other Web Container. Will that makes RoR application more scalable? I'm not sure. But it will increase RoR momentum in Java shops. When you talk about RoR to a java shop, the first question they have is "Will it run on Tomcat|WebLogic|WhebSphere|...?"

JRuby will take the top spot for scripting the Java platform

To the demise of Groovy, JRuby will take the spotlight. The main reason is the previous prediction. Once you can run RoR on a Java application server, nobody will need Grails. Grails is the only use of Groovy that create adoption.... Unless some other killer Groovy application, tool or framework is created.

RoR adoption continue

That's a fairly conservative prediction. RoR as a lot of momentum.

Java 6 adoption will start slowly in Q3

While Java 6 is out. It's adoption will grow slowly and will mainly be driven the scripting language support. Java 5 had many compelling reason to get adopted by many shops, but many many many application are still running on Java 1.4. Beside scripting support, there is nothing compelling enough in Java 6 to make it's adoption within the enterprise faster that Java 5.

Something will happen in Java build tool space

A lot of people are tired of Ant . Maven is cool, but lacks flexibility. Scripting language is getting more attention... We have Gant, Raven, JRake and many other existing or yet to be created build tool that use scripting language. By the end of the year, one of them will start getting a lot of traction. My best guess for now is Raven.

Java Specification Requests will become less and less relevant

The JCP is not working very well. It's too lengthy. Design by comity does not work well. Many JSR do not stand the sand of time. Today JSR mostly reflect some existing API with less feature (JPA vs Hibernate for example). They do not offer innovation, they just tend to seal mature innovative technology in the platform. New language features takes too long to traverse the JCP and with the open sourcing of Java, it will become easier for one group to add new feature to the language and to make a Java distribution of it's own. And with JSR like JSR-277 that create more turmoil than solve any problem, more and more people loose interest and faith in the process. Sun is not even interested in really supporting existing JSRs. We have a JSR for Groovy, but Sun hire the JRuby developers without giving any resource to Groovy. That's it! I made my prediction for 2007. This is probably my last post of the year, I will try to post a bit more often next year! In the mean time, have a Great Christmas and a really Happy New Year!

DB2 JDBC Driver hate my Date!

It's been a long time since I worked on a project that uses DB2 for the database. I always preferred DB2 to Oracle because it consume less resources (and it's much easier to install) on a developer machine.

But today I hit a strange issue...

I need to create a query that has a condition on a DATE column in some database. So my Java method that needs to do the query, I receive a java.util.Date argument. This method uses Spring-Framework Hibernate templates to do the query. Basically my query looks like this :

getHibernateTemplate().find("from Stuff s where s.effectiveDate <= ?", today)

I run a unit test that uses HSQLDB and every thing is fine.

But when I ran the same query in the application running on top of DB2, I got a nice SQLException from the DB2 JDBC Driver. The cause of the exception is :

com.ibm.db2.jcc.a.SqlException: DB2 SQL error: SQLCODE: -301, SQLSTATE: 07006, SQLERRMC: 3

The specified SQLSTATE says that this has something to do with data conversion. Huh! I have a DATE column and I pass a Date object! That should be fine (actually it is fine with MySQL, Oracle, HSQLDB and probably many other).

After a googling a bit, I found out that DB2 (the JDBC Driver) expect to receive either a java.sql.Date or a java.sql.Timestamp (depending on the type of the column). So in my case, I had to pass a java.sql.Date.

The fix is simple, I just have to create a java.sql.Date when doing the request :

getHibernateTemplate().find("from Stuff s where s.effectiveDate <= ?", new java.sql.Date(today.getTime()))

In my opinion, this is insane! It is the JDBC driver job to convert the passed data-type to something the database can handle.