@RequiredUnlessEnvironmentThe @RequiredUnlessEnvironment annotation is applied to a field annotated with @Option or
@Arguments to indicate that the option/argument must be specified unless some environment variable
is specified. This is typically used when your program automatically reads a default setting from the environment but
allows the user to override it via an option e.g.
@Option(name = "--server",
arity = 1,
description = "Specifies the server to connect to.")
@RequiredUnlessEnvironment(variables = { "MY_SERVER" })
private String server = System.getenv("MY_SERVER");
When a field is marked with @RequiredUnlessEnvironment it only becomes required if none of the specified
environment variables are set. As seen in this example your code remains responsible for populating your
option/argument from the environment variable appropriately.
If the user fails to supply the option/argument and no suitable environment variable is set then an error will be thrown during parsing
If you want to require an option regardless then you should use @Required
This documentation is itself open source and lives in GitHub under the docs/ directory.
I am not a professional technical writer and as the developer of this software I can often make assumptions of
knowledge that you as a user reading this may not have. Improvements to the documentation are always welcome, if you
have suggestions for the documentation please submit pull requests to the main branch.