I have been using the distroless Docker base images to package my applications, mainly since I want slim and simple image without unnecessary cruft. However, they are based on Debian, and Debian is unfortunately not so diligent to fix serious security issues as other distributions like Ubuntu or Alpine. If you scan a distroless image with the grype tool, you get this result: $ grype gcr.io/distroless/java17-debian11 NAME INSTALLED FIXED-IN TYPE VULNERABILITY SEVERITY libharfbuzz0b 2.

Docker’s official documentation on how to enable multi-platform Docker builds is a bit intimidating, suggesting you to run the Docker image tonistiigi/binfmt in privileged mode on your machine. I searched for alternatives on Ubuntu, and found this very detailed description. However, with recent versions of Ubuntu and Docker, it is now much easier than that: Install QEMU’s static user mode emulation binaries: sudo apt install qemu-user-static Install Docker Engine with Buildx support according instructions here (do not install docker-ce or docker.

Sometimes you want to verify that your program actually logs what it is supposed to be logging. When using Apache Log4j 2 as logging framework, it can be done like this: Include this dependency (for Maven, adjust appropriately for other build systems): <dependency> <groupId>org.apache.logging.log4j</groupId> <artifactId>log4j-core</artifactId> <type>test-jar</type> <scope>test</scope> </dependency> Import some stuff: import org.apache.logging.log4j.core.Logger; import org.apache.logging.log4j.core.LoggerContext; import org.apache.logging.log4j.test.appender.ListAppender; Add a ListAppender to the logger you are interested in: var loggerContext = LoggerContext.

In my Maven build, I use exec-maven-plugin to run an external tool for Java code generation. In this case the flatbuffers compiler (flatc). By default, flatc always runs, so you always get a new .java file. This will always trigger Java compiler to run, which will in turn always trigger jar packaging to run, etc. I would like flatc to only run if it’s source file is updated, so I can get a properly incremental build and avoid needlessly recompiling.

Android TV is included in some modern Smart TVs, and there are also external set-top-boxes to get Android TV for any TV with HDMI input. However, there are also some set-top-boxes which almost, but not quite, support Android TV. With not so much extra effort, it is possible to make an Android app supporting those fake Android TV devices as well as the real ones. In addition to the guidelines from Google for building Android TV apps, do this to support the fake TV Android TV devices as well:

After listening to a presentation about Domain Driven Security, I got some additional insights about what a data structure (as opposed to OOP object) should be able to do. Data structures (I call them struct) should have a subset of OOP features which I think is useful and harmless. A struct should allow constructors. Such constructors can have two purposes, to convert one type of data into another and to validate the input.

Several popular statically typed programming languages, including C++, Java and C#, have a serious design flaw. They make no useful distinction between objects in the OOP sense and plain data structures. A plain data structure should only be a dumb container for data. It should not have any behaviour, only simple accessors for data items in it. It should not be possible to override data accessors. It should be clear and transparent what it does.

In their quest to promote Reactive, Typesafe is beating up a straw man by portraying blocking I/O in a particularly stupid way which is rarely (if ever) done in practice. In a recent webinar, I found this slide which suggests that a blocking I/O operation will waste CPU time while waiting for the I/O to complete. If I understand it correctly, it does not actually work like this in any reasonable runtime environment / operating system.

I want a simple, fast and lightweight text editor for my Linux desktop. I don’t want to learn a lot of new arcane key bindings, so not Vim or Emacs. I want a real GUI desktop application, not a console based one, so not nano (even though nano is nice when you only have a text console available). I don’t want a full-blown IDE for programming (I already have that) so I don’t need syntax highlighting and similar features.

I regularly use Swedish keyboard layout, but I keep the English layout around in case I would like to temporary switch to it. Ubuntu 14.04 sometimes mess this up and I suddenly get English layout when I log in. I fix this by installing dconf-editor, go to desktop/ibus/general, and make sure that the values engines-order and preload-engines are the same and in the desired order with the default layout first.