Can't handle main argument that is a String as stated in the documentation

[npeder]

In the documentation (http://jcommander.org/#_main_parameter) it's stated that:

This parameter can be either a List<String> or a single field (for example a String or a type that has a converter, e.g. File), in which case there needs to be exactly one main parameter.

In the method com.beust.jcommander.JCommander#getMainParameter(java.lang.String) a ParameterException is thrown if the parameter field is not a List type

[remkop]

You may be interested in picocli. It uses @Option for named options and @Parameters for positional parameters, where both can be strongly typed: https://picocli.info/#_positional_parameters