Ideas on Apache karaf shell

Ideas on Apache karaf shell

i would like to share some ideas on Apache karaf shell.
karaf shell is based on apache felix gogo.
If you want to create a new command, you have to extends org.apache.karaf.shell.console.AbstractAction or XxxCommandSupport.

public   class  CatAction  extends  AbstractAction {
protected  Object doExecute()  throws  Exception {
// todo something here
}
}

and then add to blueprint config, would be something like this:

< blueprint  xmlns ="http://www.osgi.org/xmlns/blueprint/v1.0.0" >
     < command-bundle  xmlns ="http://karaf.apache.org/xmlns/shell/v1.0.0" >
         < command  name ="shell/cat" >
             < action  class ="org.apache.karaf.shell.commands.CatAction" />
         </ command >
        
     </ command-bundle >
</ blueprint >

it's somewhat a little bit verbose in my opinion.

i would perfer something like this:

@CommandProvider(scope  =   " shell " , name  =   " ShellCommandProvider " , description  =   " Unix Shell alike commands. " )
public   class  ShellCommandProvider {

@Option(name  =   " -n " , aliases  =  { " --show-line-number " }, description  =   " The number the output lines, starting at 1. " )
private   boolean  displayLineNumbers;

@Argument(name  =   " paths or urls " , description  =   " A list of file paths or urls to display separated by whitespaces (use - for STDIN) " , required  =   true , multiValued  =   true )
private  List paths;

@Command(scope = " my_scope " , options  =  {  " displayLineNumbers "  },arguments = { " paths " }, description  =   " Displays the content of a file or URL. " )
public   void  cat(CommandSession session)  throws  Exception {
// todo something here
}


@Argument(name  =   " paths or urls " )
private  String arg1;
@Command(options  =  {  " displayLineNumbers "  },arguments = { " arg1 " })
public   void  cat1()  throws  Exception {
 // todo something here
}

}

1. The CommandProvider no need to extends some class or implements some interface, and  it groups a set of command.
2. Each method can be a command by annotated with @Command, and opt or arg can be shared by different commands.
3. The scope specified at @CommandProvider which is shared by all the commands within this provider. and also each command can override the scope.

i.e. options = { "displayLineNumbers" }, it ref the opt by the field name. and also the same for arguments. the order indicate the index of the opt or arg.
arguments = { "arg1","arg2" }: means the command will accept the args in order: arg1 arg2

finally, add to blueprint config:

< blueprint >
     < shell:command-provider  class ="org.apache.karaf.shell.commands.ShellCommandProvider" >
        < shell:property  name ="bundleContext"  ref ="blueprintBundleContext" />
         any standard blueprint elements here
     </ shell:command-provider >
</ blueprint >

thats it.
any ideas are welcome.