uk.ac.ed.epcc.webapp.apps

Class Options.Instance

java.lang.Object

uk.ac.ed.epcc.webapp.apps.Options.Instance

Enclosing class:

Options

public class Options.Instance
extends java.lang.Object

An instance of an Options object contains all options found in arguments on a command line. The choice of options is taken from the set of options Options presents. All constraints applied by Options and the Options it contains are used when extracting options from command line arguments

Method Summary

Modifier and Type	Method and Description
boolean	containsOption(Option opt) Tests to see if the specified option has an instance in this object
boolean	containsOption(java.lang.String name) Tests to see if the specified option has an instance in this object.
Option.Instance	getOption(Option opt) Returns the instance of the specified option that is stored in this Options instance, or null if there is no instance of the specified option here.
Option.Instance	getOption(java.lang.String name) Returns the instance of the specified option that is stored in this Options instance, or null if there is no instance of the specified option here.
java.util.LinkedList<java.lang.String>	parse(java.util.LinkedList<java.lang.String> argQueue)
java.util.LinkedList<java.lang.String>	parse(java.lang.String[] arguments) Parses a set of arguments, extracts options from them and stores them in this instance.
void	validate() Makes sure all required options have instances in this Options instance.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

containsOption

public boolean containsOption(Option opt)

Tests to see if the specified option has an instance in this object

Parameters:

opt - The option to check for

Returns:

true if there is an instance of the specified option in this object. false otherwise.

containsOption

public boolean containsOption(java.lang.String name)

Tests to see if the specified option has an instance in this object. The option may be specified by long name or short name

Parameters:

name - The long or short name of the option to look for

Returns:

true if there is an instance of the specified option in this object. false otherwise.

getOption

public Option.Instance getOption(Option opt)

Returns the instance of the specified option that is stored in this Options instance, or null if there is no instance of the specified option here.

Parameters:

opt - The option to check for

Returns:

The instance of opt, or null if opt doesn't have an instance stored here.

getOption

public Option.Instance getOption(java.lang.String name)

Returns the instance of the specified option that is stored in this Options instance, or null if there is no instance of the specified option here. The option may be specified by long name or short name

Parameters:

name - The long or short name of the option to look for

Returns:

The instance of opt, or null if opt doesn't have an instance stored here.

parse

public java.util.LinkedList<java.lang.String> parse(java.lang.String[] arguments)
                                             throws java.lang.IllegalArgumentException

Parses a set of arguments, extracts options from them and stores them in this instance. All arguments that are not options are returned in the order they were discovered. Options are identified by the following properties:

• An argument beginning with -- (double hyphen) is processed as an option specified by it's long name.
• An argument beginning with - (hyphen) is processed as an option or several options specified by it's/their short name.
• The arguments - and -- are not treated as options. They are treated as non-option arguments.

Once an option is identified, it is processed in the following way:

• If the argument holds an option's long name:
• If it a value separator, it's long name is taken to be the argument string up to but not including the value separator. It's value is the argument string from the first character after the value separator to the end of the argument
• If the argument doesn't contain a value separator, the entire argument is taken to be the option's long name
• If the argument holds and option's short name:
• If it contains contains a value separator, it's short name is taken to be first non hyphen character in the argument.
• If the second character is a value separator, the value of the option is the rest of the argument after the value separator.
• If the value separator occurs later in the argument, the value of the option is taken to be the argument string from immediately after the second character to the end of the argument. Using this mechanism, property key-value pairs can be set.
• If there is no value separator, each character of the argument after the first hyphen is taken as the short name of an option
• If the option takes an argument and the argument but no value separator was present, the next argument is taken to be the value.

Example 1: Below are options, a, b and c. a and c take arguments. b does not.

-abc arg1 arg2 arg3 arg4

This produces the following result:

a = arg1
b (no value)
c = art2
remaining arguments = arg3 and arg4

Example 2: Below are options, P, assign-arg and flag. All take arguments except flag.

-Pprop=value --assign-arg=val arg1 --flag arg 2

This produces the following result:

P = prop=value
assign-arg = val
flag (no value)
remaining arguments = arg1 and arg2

Parameters:

arguments - The arguments to parse and extract options and values from

Returns:

A list of all arguments that are not options or values, in the same order they appeared in the specified arguments

Throws:

java.lang.IllegalArgumentException

parse

public java.util.LinkedList<java.lang.String> parse(java.util.LinkedList<java.lang.String> argQueue)

validate

public void validate()
              throws java.lang.IllegalStateException

Makes sure all required options have instances in this Options instance.

Throws:

java.lang.IllegalStateException - If a required option does not have an instance in this Options instance.