joptsimple

Interface OptionSpec<V>

Type Parameters:

V - represents the type of the arguments this option accepts

All Known Implementing Classes:

AbstractOptionSpec, ArgumentAcceptingOptionSpec, NonOptionArgumentSpec, OptionSpecBuilder

public interface OptionSpec<V>

Describes options that an option parser recognizes.

Instances of this interface are returned by the "fluent interface" methods to allow retrieval of option arguments in a type-safe manner. Here's an example:

     OptionParser parser = new OptionParser();
     OptionSpec<Integer> count =
         parser.accepts( "count" ).withRequiredArg().ofType( Integer.class );
     OptionSet options = parser.parse( "--count", "2" );
     assert options.has( count );
     int countValue = options.valueOf( count );
     assert countValue == count.value( options );
     List<Integer> countValues = options.valuesOf( count );
     assert countValues.equals( count.values( options ) );
 

Author:

Paul Holser

Method Summary

Modifier and Type	Method and Description
boolean	isForHelp() Tells whether this option is designated as a "help" option.
List<String>	options()
V	value(OptionSet detectedOptions) Gives the argument associated with the given option in the given set of detected options.
default Optional<V>	valueOptional(OptionSet detectedOptions) Gives the argument associated with the given option in the given set of detected options as an Optional.
List<V>	values(OptionSet detectedOptions) Gives any arguments associated with the given option in the given set of detected options.

Method Detail

values

List<V> values(OptionSet detectedOptions)

Gives any arguments associated with the given option in the given set of detected options.

Specifying a default argument value for this option will cause this method to return that default value even if this option was not detected on the command line, or if this option can take an optional argument but did not have one on the command line.

Parameters:

detectedOptions - the detected options to search in

Returns:

the arguments associated with this option; an empty list if no such arguments are present, or if this option was not detected

Throws:

OptionException - if there is a problem converting this option's arguments to the desired type; for example, if the type does not implement a correct conversion constructor or method

NullPointerException - if detectedOptions is null

See Also:

OptionSet.valuesOf(OptionSpec)

value

V value(OptionSet detectedOptions)

Gives the argument associated with the given option in the given set of detected options.

Specifying a default argument value for this option will cause this method to return that default value even if this option was not detected on the command line, or if this option can take an optional argument but did not have one on the command line.

Parameters:

detectedOptions - the detected options to search in

Returns:

the argument of the this option; null if no argument is present, or that option was not detected

Throws:

OptionException - if more than one argument was detected for the option

NullPointerException - if detectedOptions is null

ClassCastException - if the arguments of this option are not of the expected type

See Also:

OptionSet.valueOf(OptionSpec)

valueOptional

default Optional<V> valueOptional(OptionSet detectedOptions)

Gives the argument associated with the given option in the given set of detected options as an Optional.

Specifying a default argument value for this option will cause this method to return that default value even if this option was not detected on the command line, or if this option can take an optional argument but did not have one on the command line.

Parameters:

detectedOptions - the detected options to search in

Returns:

the argument of the this option as an Optional

Throws:

OptionException - if more than one argument was detected for the option

NullPointerException - if detectedOptions is null

ClassCastException - if the arguments of this option are not of the expected type

See Also:

OptionSet.valueOf(OptionSpec)

options

List<String> options()

Returns:

the string representations of this option

isForHelp

boolean isForHelp()

Tells whether this option is designated as a "help" option. The presence of a "help" option on a command line means that missing "required" options will not cause parsing to fail.

Returns:

whether this option is designated as a "help" option