« Posts under Technobable

Run a huge query as fast and safely as possible

September 9, 2011 / posted in sql, Technobable / No Comments

Use this as a last resort

Queries that take a long time are generally a bad thing. If your application requires these kinds of measures to perform its duties, then chances are you really need to revise your table structures and/or you queries – ideally these queries should take seconds at the most, while data warehouse type reporting queries should be on the order of minutes. That said, sometimes you may need to update your entire schema, delete columns on a table with millions of records, or run a stored proc that goes in and cleans up data across several…

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Configuring Data Sources, JBoss 7

August 10, 2011 / posted in Jboss, Technobable / No Comments

Yep it’s gonna be a big year for JBoss AS 7

This will be the first in a series I’ll be writing on JBoss’ new application server version 7. Lately I’ve been playing around with JBoss AS 7 recently, and all I can say is.. !@#%, NICE! I downloaded 7.0 with the expectation that it would honor a lot of the previous version’s overall approach and layout. I was in for a BIG surprise. It comes off as a total rewrite, leveraging a lot of the latest and greatest technologies and frameworks – things like Weld…

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Configure ssh authorized keys for cvs access

January 3, 2011 / posted in Technobable / No Comments

Continous Integration

Lately I’ve been working on adding Hudson as the continuous integration (CI) server for projects at work. The whole notion of CI merits an entire discussion, but suffice to say it’s a very clean, approach that helps automate the build process particularly if you run manual builds that use prompted shell scripts.

After looking at a few solutions, Hudson seemed from many accounts to be the easiest to get running, and pretty flexible when integrating into an existing build system. Add to the resume that it could run in a servlet container, divorcing…

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Write a Stored Procedure in Postgres 8+

May 5, 2010 / posted in sql, Technobable / No Comments

Stored Procs

Sometimes as a developer we’re tasked with data intensive work like importing data into a database, cleaning up sets of incomplete records or transferring data from one table to another through some kind of filter. While our application would normally be in charge of creating and maintaining the data, sometimes we don’t want to end up writing an entire module or mini application to address these tasks. Since they’re data intensive, a stored procedure might be a good approach to take. Stored procedures are a type of program written using a more robust version of sql (structured query…

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XML, Xalan, Endorsed dirs and &..

January 28, 2010 / posted in Jboss, Technobable / 3 Comments

So recently, we’ve been working on a project that makes use of OpenSAML. As it turns out OpenSAML required newer Xalan libraries (2.7.1 to be precise), the kind that don’t ship with the older incarnation of jboss we are using for the project – version 4.02. Some of you might be more familiar with the jboss system properties and will know there’s a property jboss used specifically to override the standard xml libraries that ship with the jdk/jre (entry in the console output bolded and marked with a *). Jboss will allow you to pass in…

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Java, XML and XStream

January 22, 2010 / posted in Java, Technobable, xml / 9 Comments

What’s an object/xml serializaing/deserializaing library?

If you’ve never worked with an object/xml serializer and are considering writing your own from scratch, you may want to consider using a library like XStream. XStream is very good at moving java into xml and back. It allows a high level of control over how the xml can be organized and structured and even allows the user to create their own converters for even more flexibility.

But still, why use something like this when you can be perfectly happy writing your own data conversion scheme? The problem really boils down to…

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5 ways to make XML more XPath friendly

January 19, 2010 / posted in Technobable, xml / No Comments

As java developers we should always do what we can to optimize outbound xml from our side of the fence. I mean, its our job to build and design awesome, elegant and efficient software whenever possible right? We have our data and we want to serialize it into xml, how can we make our xml as efficient and xpath friendly as possible?

1) Keep the structure simple

Consolidate data nodes whenever possible before marshaling your object into xml. You really don’t want to have to resort to using xpath for any unnecessary lookups across nodes. Keep those lookups confined to…

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Basic Ant scripts

January 13, 2010 / posted in Technobable, xml / No Comments

What’s an Ant script? Do I need bug spray?

Ant is a scripting tool commonly used to build, compile and deploy projects. This is in no way an all encompassing inventory of what Ant can do. It is extensible and its instructions are expressed in an xml format whose nodes comprise a framework of abilities designed to make menial tasks automated.

From a developer’s perspective, the most basic Ant tasks are the compile, package and copy tasks. All java projects must do these three things many, many, many times during a development cycle. Its very boring and tedious if you…

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All things XPath

January 10, 2010 / posted in Technobable, xml / No Comments

What’s XPath?

So XPath is really just a means of accessing data on xml nodes. XML has structure, with node and branches and attributes; XPath is the notation we use to express which nodes, branches or attributes we want to access. XSL makes use of this notation in order to change the structure and layout of an XML document. The process of changing one form of xml into another is called an XSL Transformation, or xslt for short.

The Basics!

If you’ve ever laid out a web page, YOU ALREADY KNOW XPATH! More specifically, if you have ever used…

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N-Tier architecture

January 5, 2010 / posted in Technobable / No Comments

History Lesson

Long, long ago.. in a galaxy far, far away… People once known as computer nerds started writing code… They walked 20 miles a day to get to the keyboard, and walked 20 miles more to copy a 3.5 inch floppy disk, remember those? 512k ram was huge! Well, back in those days people used to program applications with a procedural approach. Procedural programming was a logical, step by step approach to solving problems. Applications back then were much simpler, required much less complexity and were quite happy working within these boundaries.

Eventually, applications started to become interdependent, and…

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