Note to self

fix "There is no connected camera" on my Macbook Pro

note to self: sometimes it happens that applications cannot find a camera on my system, although it is definitely built in and not broken. This can be solved by stopping all applications that may be using the camera and then in a terminal run sudo killall VDCAssistant thanks to for this solution (check that link for further details)

Apache VirtualHost on Mac OSX

note to self: to set up a virtual host named viho for local web development testing on OSX El Capitan (and probably earlier): define an alias name in /etc/hosts: localhost viho ::1 localhost viho setup the virtual host configuration file /etc/apache2/other/viho.conf: <VirtualHost *:80> DocumentRoot "/path/to/where/the/files/are" ServerName viho </VirtualHost> browse to http://viho/ and enjoy.

Apache on Mac OSX El Capitan

Note to self: To start or stop the Apache webserver on Mac OSX El Capitan, use the terminal: sudo apachectl start sudo apachectl stop sudo apachectl restart The configuration is found in /etc/apache2/httpd.conf. The default DocumentRoot directory is /Library/WebServer/Documents. Additional configuration files should be put in /etc/apache2/other/*.conf files.

Spring-Boot, Spring profiles and configuration files

Note to self: When using Spring-Boot, use application.conf as a base configuration for the needed values. Configuration values for the specific profile go into the application-<profile>.config file. Profiles are activated by using either the<profile> VM flag or<profile> commandline arg.

Completely wipe a disk drive

I just need to completely wipe two hard disks (/dev/sda and /dev/sdb) in an old linux computer. To do this I booted a knoppix system and then ran the following commands: shred -vfz /dev/sda shred -vfz /dev/sdb

Overloading/Overwriting of methods

to keep in mind: Overloading is the creation of a method in a class with the same name as an already existing method, but with different arguments. Overwriting is the creation of a method in a derived class with the same name as an already existing method in the base class and with the same arguments