If a @Command-annotated method is in a class extending a @Command-annotated superclass, things break (another subcommand named [method] already exists for command [command])

[BeeeWall]

Example:

SuperClass.java

import picocli.CommandLine.Command;

@Command(name="super")
public class SuperClass implements Runnable {

	@Override
	public void run() {
		// TODO: Implement this method
	}
	
}

SubClass.java

import picocli.CommandLine.Command;

@Command(name="sub")
public class SubClass extends SuperClass {
	
	@Command(name="method")
	public void method() {}
}

Main.java

import picocli.CommandLine;
import picocli.CommandLine.Command;

@Command(name="main", subcommands= {SuperClass.class, SubClass.class})
public class Main implements Runnable {

	@Override
	public void run() {
		// TODO: Implement this method
	}

	public static void main(String[] args) {
		CommandLine.run(new Main(), "");
	}
}

The error

picocli.CommandLine$InitializationException: Another subcommand named 'method' already exists for command 'sub'
	at picocli.CommandLine$Model$CommandSpec.addSubcommand(CommandLine.java:3697)
	at picocli.CommandLine$Model$CommandSpec.addMethodSubcommands(CommandLine.java:3740)
	at picocli.CommandLine$Model$CommandReflection.initSubcommands(CommandLine.java:5950)
	at picocli.CommandLine$Model$CommandReflection.updateCommandAttributes(CommandLine.java:5930)
	at picocli.CommandLine$Model$CommandReflection.updateCommandAttributes(CommandLine.java:5914)
	at picocli.CommandLine$Model$CommandReflection.extractCommandSpec(CommandLine.java:5884)
	at picocli.CommandLine$Model$CommandSpec.forAnnotatedObject(CommandLine.java:3580)
	at picocli.CommandLine.<init>(CommandLine.java:185)
	at picocli.CommandLine.toCommandLine(CommandLine.java:2254)
	at picocli.CommandLine.access$8300(CommandLine.java:142)
	at picocli.CommandLine$Model$CommandReflection.initSubcommands(CommandLine.java:5937)
	at picocli.CommandLine$Model$CommandReflection.updateCommandAttributes(CommandLine.java:5930)
	at picocli.CommandLine$Model$CommandReflection.updateCommandAttributes(CommandLine.java:5914)
	at picocli.CommandLine$Model$CommandReflection.extractCommandSpec(CommandLine.java:5884)
	at picocli.CommandLine$Model$CommandSpec.forAnnotatedObject(CommandLine.java:3580)
	at picocli.CommandLine.<init>(CommandLine.java:185)
	at picocli.CommandLine.<init>(CommandLine.java:164)
	at picocli.CommandLine.run(CommandLine.java:1863)
	at picocli.CommandLine.run(CommandLine.java:1794)
	at Main.main(Main.java:13)
	at java.lang.reflect.Method.invoke(Native Method)
	at com.aide.ui.build.java.RunJavaActivity$1.run(SourceFile:108)
	at java.lang.Thread.run(Thread.java:764)

It works if I remove the @Command annotation from SuperClass, or it works if I turn method() into a class and add it to SubClass's subcommands, but not with SuperClass being a @Command and method() being a method.

[BeeeWall]

Oops, app screwed up and deleted my description. I've added an example now.

[BeeeWall]

If anyone else needs to find a way around this, I figured something out. I moved the annotation from SuperClass to an inner class and added InnerClass as a mixin. Everything inherits as it should, and annotated methods work.

Edit: it does mean SuperClass probably? isn't runnable, since you can't put an annotation with a name on it. But since I was just using it for a template class rather than a real one, it works.

Edit 2: or maybe it's called a nested class? I just said inner because it's inside the other, but I think it's actually called a nested class?

[remkop]

Thank you reporting this! This is a bug: while walking the class hierarchy, picocli should get attributes from the superclass, including @Command methods from the superclass, but it instead of looking at the methods of the superclass, it accidentally was getting methods from its own class.

I will have a fix for this soon.

[remkop]

I pushed a fix to the r3.9.x branch. There was a merge conflict when I tried to integrate this in master which I didn’t have time to resolve now. I’ll merge into master later.

[remkop]

Fixed in the master branch as well as the r3.9.x branch now.
Please verify.

[remkop]

Picocli 3.9.4 with a fix for this issue has been released. Enjoy!