Unable to use optional parameters in Spring-shell

Question

I'm trying to write some code in spring-shell I'm getting some issues. Please find the code below

@ShellComponent
public class CommandDemo {

    @ShellMethod(value = "This command is used to greet a user")
    public void greet(
            @ShellOption(value = "-name", help = "Give the name to great", defaultValue = "User") String name,
            @ShellOption(value = "-city", help = "Give the city name you are from") String city
            ) {

        String message = "Hello "+name;
        if(city!=null && !city.isEmpty()) {
            message+=", I'm from "+city;
        }

        System.out.println(message);
    }

}

1. When I give the help command on greet, it is giving me as no options available.

shell:>help greet
NAME
       greet - This command is used to greet a user

SYNOPSIS
       greet 

OPTIONS

2. "greet -name john" is giving me an unexpected result, my expectation is "Hello john"

shell:>greet -name john
Hello null

3. When I execute "mvn clean package" the build is getting struck at the test phase until I delete the test class 4. After deleting "SpringShellExampleApplicationTests", and when I execute the command java -jar spring-shell-example-0.0.1-SNAPSHOT.jar --debug the spring is considering --debug as the spring shell command and giving me the below error.

No command found for '--debug'
org.springframework.shell.CommandNotFound: No command found for '--debug'
        at org.springframework.shell.Shell.evaluate(Shell.java:231)
        at org.springframework.shell.Shell.run(Shell.java:140)
        at org.springframework.shell.jline.NonInteractiveShellRunner.run(NonInteractiveShellRunner.java:104)
        at org.springframework.shell.DefaultShellApplicationRunner.run(DefaultShellApplicationRunner.java:65)
        at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:762)
        at org.springframework.boot.SpringApplication.callRunners(SpringApplication.java:752)
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:315)
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1306)
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1295)
        at com.experiments.SpringShellExampleApplication.main(SpringShellExampleApplication.java:10)
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
        at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.base/java.lang.reflect.Method.invoke(Method.java:568)
        at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:49)
        at org.springframework.boot.loader.Launcher.launch(Launcher.java:108)
        at org.springframework.boot.loader.Launcher.launch(Launcher.java:58)
        at org.springframework.boot.loader.JarLauncher.main(JarLauncher.java:65)

Thanks in advance.

score 0 · Accepted Answer · answered Dec 21 '22 at 09:11

I can't tell which version of spring-shell that you are using. A possible solution with Spring Shell 3.0.0-M3 and Spring Boot 3.0.0:

public class CommandDemo {

    @ShellMethod(value = "This command is used to greet a user")
    public void greet(
            @ShellOption(help = "Give the name to great", defaultValue = "User") String name,
            @ShellOption(help = "Give the city name you are from") String city
    ) {

        String message = "Hello "+name;
        if(city!=null && !city.isEmpty()) {
            message+=", I'm from "+city;
        }

        System.out.println(message);
    }

}

The resulting help:

shell:>help greet
NAME
       greet - This command is used to greet a user

SYNOPSIS
       greet --name String [--city String]

OPTIONS
       --name String
       Give the name to great
       [Optional, default = User]

       --city String
       Give the city name you are from
       [Mandatory]

Test 1:

shell:>greet --name john --city denver
Hello john, I'm from denver

Test 2:

shell:>greet john denver
Hello john, I'm from denver

Unable to use optional parameters in Spring-shell

1 Answers1