Is a Sri Lanka visa required for German citizens?

Yes. A Sri Lanka visa for German citizens, who wish to visit this fascinating country and stay there for a short time, is required. There are 03 categories of a Sri Lanka e-Visa available to German citizens:

The Sri Lanka Tourist e-Visa: is used for tourism reasons. It is valid for 06 months from the date of issuance, allowing its holders to stay in Sri Lanka for up to 30 days from the arrival date. This is a double entry visa, thus German passport holders can use this visa to enter the country twice.
The Sri Lanka Business e-Visa is granted to German nationals who wish to participate in business-related activities in the country. This multiple-entry visa permits duration of stay up to 30 days.
The Sri Lanka Transit e-Visa is valid for up to 180 days after it is issued. It is only for travelers who are using Sri Lanka as a connecting point for further travel. This type of visa is for transit purposes only. German travelers have 48 hours to stay in the airport and wait for the next flight.