PicoCLI：如何将 @ArgGroup 用于方法？

问题描述

我希望以下代码段具有互斥的命令选项：

@Command(description = "test command")
public void test(
        @Option(names = { "-a"},required = true,arity = "0",description = "print A") boolean a,@Option(names = { "-b"},description = "pint B") boolean b) 

    // 
}

如果我将 @ArgGroup 用于类字段，那么它可以工作，但我想为方法实现相同的目标。

class TestClass{

@ArgGroup(exclusive = true,multiplicity = "1")
private Sample sample = new Sample();

public static class Sample {
    @Option(names = { "-a"},description = "print A") boolean a ;
    @Option(names = { "-b"},description = "pint B") boolean b ;
    
    }
}

解决方法

您应该能够使用带 @ArgGroup 注释的方法，就像带 @ArgGroup 注释的字段一样。

例如：

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",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");    
    }
}

当我运行它时，我看到以下输出：

setGroup was called with Sample[a=false,b=false]@7de62196
In run,sample=Sample[a=true,b=false]@7de62196

因此，您可以使用带有 @ArgGroup 注释的方法；它最初会被一个新实例调用，并且这个实例将在 setter 方法被调用后被修改。

（通过启用 picocli 跟踪，我们可以更深入地了解幕后发生的事情。）