Defining "spring.config.location" causes picocli parser to fail.

[alistairrutherford]

The Spring Boot parameter 'spring.config.location' allows you to specify an alternative location for your application.properties file. When I attempted to pass this along with other picocli define parameters it causes the parser to fail and I get help message. The only way I could get this to work was to define the 'spring.config.location' as an optional parameter. I can see why you wouldn't want to add special handling for spring boot for this so you might want to put a note into the documentation.

[remkop]

Thanks for raising this!
Improving Spring support is on the todo list so this is very useful!

My first thought is that defining --spring.config.location as a (non-required) option in the application is a good workaround. You may consider defining this as a “hidden” option if you don’t want this option to appear in the usage help message.

I’ll probably add a Spring Integration section to the user manual. Any other things that should be mentioned in this section?

[remkop]

@alistairrutherford Would you mind sharing (a potentially simplified version of) your code to show how to integrate picocli-based commands with Spring?

[alistairrutherford]

In order to use picocli with Spring Boot you create an application based on CommandLineRunner I.e.

@SpringBootApplication
public class MyApplication implements CommandLineRunner {

	@Autowired
	private MyRunner  myRunner;
	
	public static void main(String[] args) {
		SpringApplication.run(UserServiceApplication.class, args);
	}

	/**
	 * Main run method.
	 * 
	 */
	@Override
	public void run(String... args) {
		logger.info("EXECUTING : command line runner");

		CommandLine.call(myRunner, args);
	}
}

The class MyRunner is a Callable class which implements the main functionality:

@Component
@Command(name = "My Runner", mixinStandardHelpOptions = true, version = "My runner 1.0")
public class MyRunner implements Callable<Void> {

	@Option(names = { "-v", "--verbose" }, description = "Verbose mode. Helpful for troubleshooting. Multiple -v options increase the verbosity.")
	private boolean[] verbose = new boolean[0];
	
	@Option(names = { "-p1", "--param1" }, paramLabel = "Sample Param 1", description = "the sample param 1", required=true)
	private File sampleParam1;

	@Option(names = { "-p2", "--param2" }, paramLabel = "Sample Param 2", description = "the sample param 2", required=true)
	private File sampleParam1;

	@Option(names = { "--spring.config.location"}, paramLabel = "Config File", description = "the target config file", required=false, hidden=true)
	private String springConfigLocation;
	
	/**
	 * Construct service.
	 * 
	 * @param userService
	 */
	public MyRunner() {
        // Do stuff
	}
	
	/**
	 * Execute
	 * 
	 */
	@Override
	public Void call() throws Exception {

        // Do stuff

		return null;
	}
}

Note, in order the allow the Spring Boot application to accept the "spring.config.location" you simply add it to your Callable element. This will allow Spring boot to pick it up and stop picocli rejecting an unknown parameter.

You would follow this pattern for any other Spring Boot parameter you required.

[remkop]

Perfect, thank you!

[remkop]

For the next release, I updated the user manual: Dependency Injection is now a top-level section, with subsections for Guice, Spring Boot and Micronaut.

I used your code to create the Spring Boot example, and mentioned the --spring.config.location tip.
Can you verify?

If you run gradlew ascii the updated user manual is generated in build/docs/html5/index.html.

[alistairrutherford]

I have reviewed the documentation section and it's looks fine.

[remkop]

Thanks for the confirmation!