PicoCLI : How can I use #ArgGroup for a method? - picocli

Question

I want to have mutually exclusive command options for the below snippet :
#Command(description = "test command")
public void test(
#Option(names = { "-a"}, required = true, arity = "0", description = "print A") boolean a,
#Option(names = { "-b"}, required = true, description = "pint B") boolean b)
//
}
If I use #ArgGroup for a class field then It works but I want to achieve the same for methods.
class TestClass{
#ArgGroup(exclusive = true, multiplicity = "1")
private Sample sample = new Sample();
public static class Sample {
#Option(names = { "-a"}, required = true, arity = "0", description = "print A") boolean a ;
#Option(names = { "-b"}, required = true, description = "pint B") boolean b ;
}
}

Answer 1

You should be able to use an #ArgGroup-annotated method, just like an #ArgGroup-annotated field.
For example:
class SomeCommand implements Runnable {
private Sample sample;
#ArgGroup(exclusive = true, multiplicity = "1")
void setGroup(Sample sample) {
System.out.printf("setGroup was called with %s%n", sample);
this.sample = sample;
}
static class Sample {
#Option(names = "-a", required = true, arity = "0", description = "print A") boolean a ;
#Option(names = "-b", required = true, description = "print B") boolean b ;
public String toString() {
return String.format("Sample[a=%s, b=%s]#%x", a, b, hashCode());
}
}
public void run() {
System.out.printf("In run, sample=%s%n", this.sample);
}
public static void main(String... args) {
//System.setProperty("picocli.trace", "DEBUG");
new CommandLine(new SomeCommand()).execute("-a");
}
}
When I run this, I see the following output:
setGroup was called with Sample[a=false, b=false]#7de62196
In run, sample=Sample[a=true, b=false]#7de62196
So, you can use an #ArgGroup-annotated method; it will initially be invoked with a new instance, and this instance will be modified after the setter method was called.
(We can get more insight into what is happening under the hood by enabling picocli tracing.)