java – Code Trips & Tips

Integrating Open Policy Agent with Spring Security Reactive and JSON Web Tokens

February 5, 2021

We present a Java library that simplifies adopting the Open Policy Agent server to manage user authorization for a Spring Boot microservice, while also managing API Token (JWT) authentication. Motivation Spring Security assumes a fairly simplistic Role-Based access control (RBAC) where the service authenticates the user (via some credentials, typically username/password) and returns a UserDetails … More Integrating Open Policy Agent with Spring Security Reactive and JSON Web Tokens

A better mousetrap (or, how to improve on Java 8 Optional)

November 8, 2016

Overview The java.util.Optional class is a great addition in Java 8 as it enables a more expressive way of conveying the concept of a library API return value that may not be there. While it is not meant to replace the use of null values in code (and you will get warnings not to use … More A better mousetrap (or, how to improve on Java 8 Optional)

Using Java 8 Optional and Functional interfaces to reduce boilerplate

May 29, 2016

The code presented here makes judicious use of Optionals, Functionals and the new Streaming interfaces.
It’s all very awesome, and makes me wonder: Java, what took you so long? … More Using Java 8 Optional and Functional interfaces to reduce boilerplate

Do Not Allow Bad Smells In Your Code

January 25, 2015

Smelly Code I have recently been involved in a distributed SaaS application that was originally built by an offshore team; the chosen technologies (REST, Java, MongoDB) were actually valid technical choices for the problem at hand: they then proceeded to get it spectacularly wrong with a bloated (and unmanageable) data schema and an even worse … More Do Not Allow Bad Smells In Your Code

Data-driven tests for Spring Data (MongoDB)

January 16, 2015

When testing a project that uses Spring Data repositories, we may want to insert ‘known-good’ data into arbitrary MongoDB collections, reading it, for example, from JSON iles (typically somewhere in the test/resources subtree). However, some of the data stored in Mongo is in BSON format, which extends the plain JSON format with some Object types … More Data-driven tests for Spring Data (MongoDB)

Code Reviews

September 30, 2014

As anyone who has worked with me is well aware, I’m a great believer in code reviews – there is much to be said about a number of positive impacts on the project (and the developers’ professional growth too). This is a great article that sums up very well the benefits, as well as a … More Code Reviews

Run Android tests in a connected device

January 18, 2011

Not quite sure as to why it never occurred to me, but it is totally possible and legal to run unit tests inside a real device, connected to your dev box via a USB cable.An obvious advantage is that you are now running your tests in a more “realistic” environment; there are no drawbacks that … More Run Android tests in a connected device

Dump CPU temperature data to a file in Ubuntu

November 21, 2010

Update: I’ve figured out that it makes a lot more sense to have a reading of the CPU load to correlate with the temperature reading, so I’ve added that too using /usr/bin/uptime.I have written a very simple Java utility to take readings from the CPU temperature sensors utility (/usr/bin/sensor) and dump it to a CSV … More Dump CPU temperature data to a file in Ubuntu

Code Trips & Tips

Adventures in developing distributed systems in Java and Python

Category: java