Living in the Future with IPv6

It’s not quite flying cars, but since yesterday I’m living in the future. IPv6 has arrived at my home network after I switched to a new VDSL contract. I had to activate it manually in my FritzBox home router though, but as far as I can tell, things are working fine. Now I’m able to use Google services and read Heise Online via IPv6!

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Installing Oracle’s JDK on Debian/Ubuntu

Due to licensing issues, Linux distributions don’t ship Oracle Java packages anymore. In many cases, that doesn’t matter since you can just use OpenJDK. But if you do need Oracle’s JDK, Debian packages are a bit more convenient than handling tarballs because they integrate nicely with the rest of the system. Fortunately, there’s a simple way of creating a Debian package from the official JDK using the java-package tool.

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Managing Docker Container Updates

When running a Debian/Ubuntu-based server, it’s relatively easy to figure out whether updates need to be installed. Tools based on apt work very well in this regard and even offer advanced features like unattended updates. Not so with services running in Docker containers.

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Converting Images to ASCII Art

I’ve been playing with Docker a lot lately. Docker is a tool for creating lightweight virtual environments based on Linux containers. They are extremely useful for running services, but you can also use them for running one-off tasks that you don’t want to run on the host system directly. Since a container shares the host machine’s kernel, startup is instantaneous and there’s no extra memory footprint. Think of Linux containers as generalized chroot environments or as extremely lightweight virtual machines.

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Maven: Discovering Dependency Conflicts

Among other things, Maven’s dependency plugin displays the result of Maven’s dependency resolution mechanism. The output of the dependency:tree goal makes it easy to see where transitive dependencies come from. This week I discovered that recent versions of the plugin also support a verbose flag that lists conflicts and shows how Maven resolved them.

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Testing equals() with Guava

I’ve long held the opinion that Guava belongs on every Java classpath because its design and the quality of its implementation surpass other comparable utility libraries (and sometimes even the JDK). Guava’s testlib is pretty cool, too, even though it’s not as widely known.

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Enabling Hibernate Support in Ubuntu 14.04 LTS

In this article, I’ll show you how to enable hibernate support in Ubuntu 14.04 (“Trusty Tahr”) by making a “Hibernate” menu entry appear in Unity’s global system pulldown menu. The Ubuntu developers disabled this a couple of years ago because hibernate didn’t work reliably on all systems – proceed at your own risk!

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