Annotation Type CommandLine.Command

Enclosing class:
CommandLine

@Retention(RUNTIME) @Target({TYPE,LOCAL_VARIABLE,PACKAGE}) public static @interface CommandLine.Command

Annotate your class with @Command when you want more control over the format of the generated help message.

 @Command(name      = "Encrypt",
        description = "Encrypt FILE(s), or standard input, to standard output or to the output file.",
        footer      = "Copyright (c) 2017")
 public class Encrypt {
     @Parameters(paramLabel = "FILE", type = File.class, description = "Any number of input files")
     private List<File> files     = new ArrayList<File>();

     @Option(names = { "-o", "--out" }, description = "Output file (default: print to console)")
     private File outputFile;
 }

The structure of a help message looks like this:

  • [header]
  • [synopsis]: Usage: <commandName> [OPTIONS] [FILE...]
  • [description]
  • [parameter list]: [FILE...] Any number of input files
  • [option list]: -h, --help prints this help message and exits
  • [footer]
  • Optional Element Summary

    Optional Elements
    Modifier and Type
    Optional Element
    Description
    boolean
    Specify true to generate an abbreviated synopsis like "<main> [OPTIONS] [PARAMETERS...]".
    Set the heading preceding the subcommands list.
    Specify one or more custom synopsis lines to display instead of an auto-generated synopsis.
    Optional text to display between the synopsis line(s) and the list of options.
    Set the heading preceding the description section.
    Optional text to display after the list of options.
    Set the heading preceding the footer section.
    Optional summary description of the command, shown before the synopsis.
    Set the heading preceding the header section.
    Program name to show in the synopsis.
    Set the heading preceding the options list.
    Set the heading preceding the parameters list.
    char
    Prefix required options with this character in the options list.
    String that separates options from option parameters.
    boolean
    Specify true to show default values in the description column of the options list (except for boolean options).
    boolean
    Specify false to show Options in declaration order.
    Class<?>[]
    A list of classes to instantiate and register as subcommands.
    Set the heading preceding the synopsis text.
    Version information for this command, to print to the console when the user specifies an option to request version help.
  • Element Details

    • name

      String name
      Program name to show in the synopsis. If omitted, "<main class>" is used. For declaratively added subcommands, this attribute is also used by the parser to recognize subcommands in the command line arguments.
      Returns:
      the program name to show in the synopsis
      See Also:
      Default:
      "<main class>"
    • subcommands

      Class<?>[] subcommands
      A list of classes to instantiate and register as subcommands. When registering subcommands declaratively like this, you don't need to call the CommandLine.addSubcommand(String, Object) method. For example, this:
       @Command(subcommands = {
               GitStatus.class,
               GitCommit.class,
               GitBranch.class })
       public class Git { ... }
      
       CommandLine commandLine = new CommandLine(new Git());
       
      is equivalent to this:
       // alternative: programmatically add subcommands.
       // NOTE: in this case there should be no `subcommands` attribute on the @Command annotation.
       @Command public class Git { ... }
      
       CommandLine commandLine = new CommandLine(new Git())
               .addSubcommand("status",   new GitStatus())
               .addSubcommand("commit",   new GitCommit())
               .addSubcommand("branch",   new GitBranch());
       
      Returns:
      the declaratively registered subcommands of this command, or an empty array if none
      Since:
      0.9.8
      See Also:
      Default:
      {}
    • separator

      String separator
      String that separates options from option parameters. Default is "=". Spaces are also accepted.
      Returns:
      the string that separates options from option parameters, used both when parsing and when generating usage help
      See Also:
      Default:
      "="
    • version

      String[] version
      Version information for this command, to print to the console when the user specifies an option to request version help. This is not part of the usage help message.
      Returns:
      a string or an array of strings with version information about this command.
      Since:
      0.9.8
      See Also:
      Default:
      {}
    • headerHeading

      String headerHeading
      Set the heading preceding the header section. May contain embedded format specifiers.
      Returns:
      the heading preceding the header section
      See Also:
      Default:
      ""
    • header

      String[] header
      Optional summary description of the command, shown before the synopsis.
      Returns:
      summary description of the command
      See Also:
      Default:
      {}
    • synopsisHeading

      String synopsisHeading
      Set the heading preceding the synopsis text. May contain embedded format specifiers. The default heading is "Usage: " (without a line break between the heading and the synopsis text).
      Returns:
      the heading preceding the synopsis text
      See Also:
      Default:
      "Usage: "
    • abbreviateSynopsis

      boolean abbreviateSynopsis
      Specify true to generate an abbreviated synopsis like "<main> [OPTIONS] [PARAMETERS...]". By default, a detailed synopsis with individual option names and parameters is generated.
      Returns:
      whether the synopsis should be abbreviated
      See Also:
      Default:
      false
    • customSynopsis

      String[] customSynopsis
      Specify one or more custom synopsis lines to display instead of an auto-generated synopsis.
      Returns:
      custom synopsis text to replace the auto-generated synopsis
      See Also:
      Default:
      {}
    • descriptionHeading

      String descriptionHeading
      Set the heading preceding the description section. May contain embedded format specifiers.
      Returns:
      the heading preceding the description section
      See Also:
      Default:
      ""
    • description

      String[] description
      Optional text to display between the synopsis line(s) and the list of options.
      Returns:
      description of this command
      See Also:
      Default:
      {}
    • parameterListHeading

      String parameterListHeading
      Set the heading preceding the parameters list. May contain embedded format specifiers.
      Returns:
      the heading preceding the parameters list
      See Also:
      Default:
      ""
    • optionListHeading

      String optionListHeading
      Set the heading preceding the options list. May contain embedded format specifiers.
      Returns:
      the heading preceding the options list
      See Also:
      Default:
      ""
    • sortOptions

      boolean sortOptions
      Specify false to show Options in declaration order. The default is to sort alphabetically.
      Returns:
      whether options should be shown in alphabetic order.
      See Also:
      Default:
      true
    • requiredOptionMarker

      char requiredOptionMarker
      Prefix required options with this character in the options list. The default is no marker: the synopsis indicates which options and parameters are required.
      Returns:
      the character to show in the options list to mark required options
      See Also:
      Default:
      ' '
    • showDefaultValues

      boolean showDefaultValues
      Specify true to show default values in the description column of the options list (except for boolean options). False by default.
      Returns:
      whether the default values for options and parameters should be shown in the description column
      See Also:
      Default:
      false
    • commandListHeading

      String commandListHeading
      Set the heading preceding the subcommands list. May contain embedded format specifiers. The default heading is "Commands:%n" (with a line break at the end).
      Returns:
      the heading preceding the subcommands list
      See Also:
      Default:
      "Commands:%n"
    • footerHeading

      String footerHeading
      Set the heading preceding the footer section. May contain embedded format specifiers.
      Returns:
      the heading preceding the footer section
      See Also:
      Default:
      ""
    • footer

      String[] footer
      Optional text to display after the list of options.
      Returns:
      text to display after the list of options
      See Also:
      Default:
      {}