Downgrade Maven version – Ubuntu 16
If you have to downgrade Maven version to an older version, you can specify this via using Pin. Open the maven.pref file within you /etc/apt/preferences.d/ folder and adapt the content depending on your own needs:
Mathematical basics – Set theory
Set A Set is a collection of objects that are distinct. Assume the following Set A has the elements a, b, c and d, so we can say A = {a,b,c,d}. In the example above, …
Code generation with Slick code generator of PostgreSQL database in Scala project
If you automatically want to generate the Tables mapping of your database tables for the use within the Slick environment, you can use the Slick code generator to achieve this task. The groundwork contains: Database …
Switch to hex-mode witin VIM and NeoVIM
If you want to see the current file in HEX mode, you can switch to Hex-Mode with the following command: If you want to switch back, you can use the following command:
Make a SSH key available that is not the default one and combine with GIT SSH command
If you want to add another SSH key to the current shell session that is not the default one, you can do the following. Export the additional key to the GIT SSH command to have …
Semi-automatic Circe decoder for JsonString of slick-pg
If you need a decoder for storing JSON to a database or implicit conversion of a com.github.tminglei.slickpg.JsonString, you can us the semi-automatic derivation of Circe. The following imports are neccessary. Let`s assume, we have the …
Akka stream with Alpakka and FTP connector – close the stream
If you use an Alpakka FTP connector, you have to close the stream at the end to finish the connection correctly. The default behavior is to sent a `akka.actor.Status.Success` message to the ActorRef. I got …
Create a new pair of ssh keys with a specific filename
If you need additional ssh keys for the work on external projects, you can create additional keys with the following command: If you have not executed the command within the .ssh folder, you should move …
Rewind the last changes within a git repository
If you hust want to rewind the last changes within a Git repository, you can do this with the following command: If you just want to rewind the changes of a single file, you can …
Import external Ivy dependencies during ammonite session
You can import external Ivy dependencies during you ammonite session. First, you have to import the Ivy (SBT) dependency (The example imports the jBCrypt library from the Maven repository). Additional information can be found at …
Update Ammonite (ammonite.io)
If you want to update ammonite, you can do this in the following manner: Note: The latest ammonite version can be found on http://ammonite.io. Just exchange the https-URL. Store the ammonite executable to the local …
Traversing the alphabet in Scala
If you need to traverse the alphabet in Scala automatically, you can create a loop that proceses the single letters. The following code was used in a Play Template (view) to traverse the alphabet and …
Permission denied while trying to connect with Docker daemon via socket
The following error occured while trying to connect to the Docker daemon after installation. The daemon was not accessible by the current user because of lack of permission. The solution is to add the current …
Tmux configuration and basic commands
Basic configuration for tmux Tmux canbe configured via .tmux.conf file within the home directory. The following .tmux.conf contains a basic configuration. Basic tmux commands To start a new tmux terminal, the following command forces the …
Git commands to delete a local tag and the corresponding remote tag
View the local tags Display the remote tags Remove the local tag with the name TAGNAME Remove the corresponding remote tag
IntelliJ IDEA VM options
Idea vmoptions The following options for the `idea64.vmoptions` file are prety useful on my system. Current system Current system and IDEA version. Ubuntu 16.04.2 LTS IntelliJ Idea IU-171.3691.12