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Category Archives: Java

Subversion, JavaHL, and Eclipse on Linux

Saturday, July 10, 2010

I normally use emacs and command line svn when working at home on Linux. Eclipse to me, in principle, is a necessary evil of programming with larger groups. But a recent volunteer project I’ve been working on for the Philippine Scholars of Minnesota is forcing me out of this habit. And with this change, I’ve [...]

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Debugging MySQL ERROR1025 – Error on rename of

Tuesday, May 18, 2010

If you ever executed the following command in mysql: alter table table drop column; and got the following error: 1025 – Error on rename of ‘.\\#sql-880_3c’ to ‘.\\ ’ (errno: 150), Don’t panic. It’s probably because you’re trying to drop a column that’s a foreign key. Execute this command: SHOW ENGINE INNODB STATUS to debug more. [...]

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Migrating from Hibernate 3.3.2, JPA 1 to Hibernate 3.5 CR2 and JPA 2

Monday, March 29, 2010

Starting with version 3.5 (currently CR2), Hibernate Annotations 3.x and Hibernate EntityManager projects have been merged into the Hibernate Core codebase as invidual modules. As a surprising addition, Hibernate Envers subproject is added as well (that’s a great thing as you get Auditing, out of box hereafter). So if you’re stuck with Hibernate 3.3.x and [...]

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Upgrading to Hsqldb 2rc8, part 1, Maven Integration

Wednesday, January 27, 2010

At my current client engagement, we make full use of hsqldb both in our unit tests and for local development. It’s a great tool, and the changes made since the last release 4 long years ago will make it an even better tool. My project has hundreds of tests making use of hsqldb, and getting [...]

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Accessing Drools 5 rules via a restful API using Drools Server and Groovy RestClient

Wednesday, December 2, 2009

If you haven’t heard about drools, you should have a look at it now. It provides multiple ways to write rules: DSL (drl files), groovy, java, excel spreadsheets or via a web interface (Guvnor). I recommend the book, Drools – JBoss Rules 5.0 by Michael Bali as its the only comprehensive documentation available on drools. [...]

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an interesting class loading issue with quartz scheduler timing (NoClassDefFoundError)

Thursday, October 29, 2009

My quartz job schedulers had a startDelay of 0 ms and a repeatInterval of 10 mins and 5 mins each. On my local environment (win/mac) and sandbox (unix) the scheduler works just fine. But in our production environment (unix), we were getting spurious java.lang.NoClassDefFoundError: Could not initialize class Foo. Now Foo was one of the [...]

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Follow RTC on Twitter

Sunday, July 26, 2009

We only tweet from the console! http://www.twitter.com/reverttoconsole

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Integrating JavaScript Tests with Continuous Integration

Monday, June 22, 2009

At my current client I’ve been building a rather complex rich client app using ExtJs. The team has written a lot of JavaScript code, and has been writing a lot of JavaScript unit tests as well. We’ve gone through several unit testing tools along the way trying to solve some logistical problems. We started with [...]

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The best 59$, a java developer can ever invest

Wednesday, June 17, 2009

If you don’t buy this now, you’re either dumb. Or just plainly stupid. For the impatient: it’s a small jar that lets you compile/run/deploy java instantly, like php. I’ts the real HOT DEPLOY that jvm lacks out of the box. No more restarting the server, ever again, even after reconfiguring Spring beans. I used this [...]

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Unit Testing JavaScript with HtmlUnit and Screw.Unit

Friday, May 29, 2009

Writing apps with today's rich client libraries such as Extjs , YUI , and JQuery really shows how much potential is still left in web development. But it takes a lot of code, and the amount of technical debt can get heavy, quickly. Good tests can help reduce this technical debt, and there are a lot of testing [...]

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