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An example of writing a potentially large amount of data directly to a zip file, item by item.

Session management in Java servlets.

VisualVM is a great tool for exploring Java applications and the JVM in which they are running. One area which has always been a bit overwhelming (to me) is the heap dump - a mass of raw information for millions of objects, which can be hard to sift through…

I have previously written about my wish to avoid being responsible for password management.  Here is the other side of the coin: Some code which (a) creates a hash for a new password, and (b) checks if a password is valid. Also included: A bonus digression on Java string immutability.

JSON is simultaneously straightforward and tricky…

In this walk-through I will take a look at AWS Cognito for user sign-up, password management and access controls, using a basic Java web application for demonstration purposes.

How to generate a free SSL wildcard certificate using Let’s Encrypt and certbot.

The other day I was working with some old relational data, where timestamps had been stored without timezone data - and not standardized to UTC…

While I was exploring Lucene as a way to improve my demo web application, I tried a few different combinations of analyzers, tokenizers and filters. It got to the point where I created a small test application for this. Along the way, I also had to dive into Lucene’s boolean query logic.

Using SPI (service provider interface) names allows us to use the Lucene CustomAnalyzer. This can be much more succinct than using the related classes directly.