Category Archives: Open Source

FileCache – a simple cache of generated static content

The FileCache sits at the core of the bankopladerne.dk backend with the following responsibilities:

* Ensure often-accessed content is cached.

* Maintain cache of files in the temporary file system while not using too much space.

* Ensure an item is only produced once in a high-traffic scenario where the same resource is requested concurrently. Continue reading

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SafeEquals

I’m currently designing a user-authentication OAuth2 based service. I’m trying very hard never ever to reveal anything about users or passwords. Credential-lookup by userid is always done twice. If the user is not found a known dummy-user is looked up … Continue reading

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Salesforce wsc hacking: yet another Open Source encounter?

As I wrote in an earlier post I’ve volunteered to become a committer to the wsc tool and are in the progress of making minor tweaks and enhancements for a coming release 23. My plan was that this release should … Continue reading

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usl4j – Ultra Simple Logging for JAVA

Back in the late 90’ties when I started programming JAVA there were no standard way of logging in JAVA programs. One usually just used System.out.println(), System.err.println() and Exception.printStacktrace(). Often applications would build homemade logging frameworks that would also log information … Continue reading

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Simple logarithm implementation in PIC assembler

Most natural observations are exponentational/logarithmic in nature. I often do simple hardware using Microchip PIC processors (usually 12F or 16F families). Hardware doing some business in the home. One such example is my Christmas-tree-lightning-controller. Basically it only turns my electric … Continue reading

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Securing J[2]EE applications, part 3

In this third article, the samples are modified to be run on JBoss (4.0.3+) and JavaDB (Derby version 10.2). The first article showed how to setup Glassfish authentication with only a single database table. The second article evovled the simple … Continue reading

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Securing J[2]EE applications, part 2

The first part, Securing J[2]EE applications, part 1, discusses a simple setup where a single database table, 2 views and a correctly configured jdbcRealm could handle the most basic authentication and authorization requirements. This second article discusses a few enhancements … Continue reading

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Securing J[2]EE applications, part 1

I’m writing a few articles about securing J2EE applications. The setup is a Glassfish v2 as application server and PostgreSQL v8.3 as database server, keeping it open-source and free 🙂 This first part discusses a simple setup where only a … Continue reading

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Why I love PostgreSQL

Now, I’ve written some ranting about why I hate MySQL, now it is time to write about another Open Source RDBMS, PostgreSQL. In this blog I am going through why I think PostgreSQL is a great database – comparable with … Continue reading

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An Open Source encounter

I really like Open Source software. I use it a lot: Linux, apache, postfix, amavis-new, clamav, openSSL, openLDAP, PostgreSQL, PHP are just a few of the OSS products I have on my servers. When developing JAVA, I use Eclipse, Ant, … Continue reading

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