java -jar <your-jar>
is, I think, the best you can do, if you want to support different operating systems as well. If a user doesn't have java command in the path, java support has not been installed as a public JRE and user should either fix the configuration or explicitly specify which private JRE is to be used. Oracle documentation explicitly states about the public JRE that
You must set the PATH environment variable to point to JAVA_HOME\bin (where JAVA_HOME is the location where you installed the public JRE) to register the JRE.
so a user should do just that. You can, however, check if JAVA_HOME is set and if java exists in the path and provide informational error message if it is not.
If you're fine with only supporting windows, you can use various .exe packaging systems to ease the process for end user. See this, this and this thread for details.