SDNotify

A simple library for Java 17+ implementing the sd_notify protocol from systemd.

<dependency>
    <groupId>de.afoo</groupId>
    <artifactId>sdnotify</artifactId>
    <version>1.0</version>
</dependency>

implementation 'de.afoo:sdnotify:1.0'

Usage

Create an instance using

SDNotify sdNotify = SDNotify.create();

This will either create an instance of ActualSDNotify or NOOPSDNotify depending on the availability of the sd_notify socket file. This means this library is usable safely whether you are running a service of Type=notify or not.

Once you have your instance, you can use it for communication between your service and systemd.

// tell systemd that your service is ready
sdNotify.ready();

// set status information for your service
sdNotify.status("currently running cleanup");

// inform systemd that your service is reloading
sdNotify.reloading();
  
// ... or stopping
sdNotify.stopping();

// Tell the watchdog, that your service is still available
// see https://www.freedesktop.org/software/systemd/man/latest/systemd.service.html#WatchdogSec=
sdNotify.watchdog();

For more comprehensive documentation, see here.