PostgreSQL XPath tutorial

In this post I’d like to show some practical examples of XML processing in PostgreSQL using XPath

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XMPP service. System Facade

In previous posts (here and here) I’ve started describing XMPP subsystem and analyzing requirements. Before we proceed with the analysis of  requirements (8)+ it’s time to create overview of current structure

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jHolidays project

Some time ago I’ve decided to create a small utility which will be able to create ICal calendar using input file (listing of events, holidays etc). Read the rest of this entry »

Oracle logging table changes

In this post I’ll put a small example of how to create stored procedure for Oracle and log changes in database table

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Abstract Factory + Composite = Composite Factory

Some time ago I’ve faced an interesting challenge. I needed to create library that provided clients with my own types (let’s call them built-in ones). On the other side I needed to allow third-parties to extend my library using their own types.

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Refactoring hierarchy construction

In this article I’d like do talk about refactoring of construction of hierarchy and high cohesion pattern.

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Factory method pattern – interesting appliance

Today I’m going to talk about factory method pattern and it’s very interesting appliance. Read the rest of this entry »

HashMap complex keys

Everybody use associative arrays. They provide mapping between key and value. In this article I’ll talk about using complex keys in java.util.HashMap<K,V> Read the rest of this entry »

Cellphone for my syster

Recently I’ve received distress call from my sister. She wants simple but elegant cellphone for herself.

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Sqlite in Java. Performance.

I’ve prepared comparison and gathered some statistical information about sqlite performance in Java. Performance overhead in auto-commit enabled mode is huge.

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