ArgsOptionParser

public class ArgsOptionParser
extends OptionSetter

Populates Option fields from parsed command line arguments.

Strings in the passed-in String[] are parsed left-to-right. Each String is classified as a short option (such as "-v"), a long option (such as "--verbose"), an argument to an option (such as "out.txt" in "-f out.txt"), or a non-option positional argument.

Each option argument must map to one or more Option fields. A long option maps to the Option name, and a short option maps to Option short name. Each option name and option short name must be unique with respect to all other Option fields within the same object.

A single option argument can get mapped to multiple Option fields with the same name across multiple objects. Option arguments can be namespaced to uniquely refer to an Option field within a single object using that object's full class name or its OptionClass alias value separated by ':'. ie

 --classname:optionname optionvalue or
 --optionclassalias:optionname optionvalue.
 

A simple short option is a "-" followed by a short option character. If the option requires an argument (which is true of any non-boolean option), it may be written as a separate parameter, but need not be. That is, "-f out.txt" and "-fout.txt" are both acceptable.

It is possible to specify multiple short options after a single "-" as long as all (except possibly the last) do not require arguments.

A long option begins with "--" followed by several characters. If the option requires an argument, it may be written directly after the option name, separated by "=", or as the next argument. (That is, "--file=out.txt" or "--file out.txt".)

A boolean long option '--name' automatically gets a '--no-name' companion. Given an option "--flag", then, "--flag", "--no-flag", "--flag=true" and "--flag=false" are all valid, though neither "--flag true" nor "--flag false" are allowed (since "--flag" by itself is sufficient, the following "true" or "false" is interpreted separately). You can use "yes" and "no" as synonyms for "true" and "false".

Each String not starting with a "-" and not a required argument of a previous option is a non-option positional argument, as are all successive Strings. Each String after a "--" is a non-option positional argument.

The fields corresponding to options are updated as their options are processed. Any remaining positional arguments are returned as a List<String>.

Here's a simple example:

 // Non-@Option fields will be ignored.
 class Options {
     @Option(name = "quiet", shortName = 'q')
     boolean quiet = false;

     // Here the user can use --no-color.
     @Option(name = "color")
     boolean color = true;

     @Option(name = "mode", shortName = 'm')
     String mode = "standard; // Supply a default just by setting the field.

     @Option(name = "port", shortName = 'p')
     int portNumber = 8888;

     // There's no need to offer a short name for rarely-used options.
     @Option(name = "timeout" )
     double timeout = 1.0;

     @Option(name = "output-file", shortName = 'o' })
     File output;

     // Multiple options are added to the collection.
     // The collection field itself must be non-null.
     @Option(name = "input-file", shortName = 'i')
     List<File> inputs = new ArrayList<File>();

 }

 Options options = new Options();
 List<String> posArgs = new OptionParser(options).parse("--input-file", "/tmp/file1.txt");
 for (File inputFile : options.inputs) {
     if (!options.quiet) {
        ...
     }
     ...

 }

 

• the getopt(1) man page
• Python's "optparse" module (http://docs.python.org/library/optparse.html)
• the POSIX "Utility Syntax Guidelines" (http://www.opengroup.org/onlinepubs/000095399/basedefs/xbd_chap12.html#tag_12_02)
• the GNU "Standards for Command Line Interfaces" (http://www.gnu.org/prep/standards/standards.html#Command_002dLine-Interfaces)

Summary

Public constructors

public ArgsOptionParser ( optionSources)

public ArgsOptionParser (Object... optionSources)

Public methods

public static String getOptionHelp (boolean importantOnly, 
                Object optionObject)

   [-option_shortname, --option_name]          [option_description] Default:
   [current option field's value in optionObject]
 

public  parse (String... args)

public  parse ( args)

public  parseBestEffort ( args)

public  parseBestEffort ( args, 
                boolean forceContinue)

public  parseBestEffort (String... args)

public void validateMandatoryOptions ()