Class Parameter
Top-level abstraction of a parameter. A parameter consists of one or more arguments (command line tokens) that have a special meaning when taken together. For example, a command-line switch "-v" is a parameter consisting of a single argument, whereas a command-line option "--file somefile.txt" is a parameter consisting of two arguments. Some parameters can be quite large, such as an option for a file compression utility that allows you to specify any number of files to comporess.
This is an abstract class. See its subclasses Switch
,
FlaggedOption
, and UnflaggedOption
for details on the various types of parameters. Functionality common to all three
types of Parameters is described below.
Each parameter has a unique ID assigned in its constructor. This ID is
used to retrieve values from the parser after the command line is parsed.
You can set the ID to any String value you wish, although in general you'll
want them to be brief and descriptive to provide a degree of documentation.
A "-h" switch, for example, might have the ID "help".
The calling program can then determine if the user specified the -h switch on
the command line with the simple call getBoolean("help")
against
the JSAPResult object produced by JSAP.parse().
- Author:
- Marty Lamb
- See Also:
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionfinal void
addDefault
(String defaultValue) Adds a single default value to any currently defined for this parameter.final String[]
Returns an array of default values for this parameter, or null if no default values have been defined.final String
getHelp()
Returns a description of the option's usage.getID()
Returns this parameter's unique ID.abstract String
A convenience method for automatically generating syntax information based upon a JSAP configuration.final String
getUsage()
Deprecated.use getSyntax() insteadfinal String
Returns the name of this AbstractParameter for the purposes of usage information.final Parameter
Sets the help text for this parameter.
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Constructor Details
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Parameter
Creates a new Parameter. Subclasses should call this constructor.- Parameters:
id
- The ID for this argument. All arguments MUST have a unique ID.
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Method Details
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getID
Returns this parameter's unique ID.- Returns:
- this parameter's unique ID.
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addDefault
Adds a single default value to any currently defined for this parameter.- Parameters:
defaultValue
- the default value to add to this parameter.
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getUsageName
Returns the name of this AbstractParameter for the purposes of usage information. The returned value is by default the id of this parameter, but can be overridden via setUsageName(String).- Returns:
- the name of this AbstractParameter for the purposes of usage information.
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getDefault
Returns an array of default values for this parameter, or null if no default values have been defined.- Returns:
- an array of default values for this parameter, or null if no default values have been defined.
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getSyntax
A convenience method for automatically generating syntax information based upon a JSAP configuration. A call to JSAP.getSyntax() returns a String built by calling getSyntax() on every parameter registered to a JSAP in the order in which they were registered. This method does not provide a help description (see getHelp()), but rather the syntax for this parameter.- Returns:
- usage information for this parameter.
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getUsage
Deprecated.use getSyntax() insteadDeprecated - use getSyntax()- Returns:
- deprecated - use getSyntax()
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getHelp
Returns a description of the option's usage.- Returns:
- a textual description of this option's usage
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setHelp
Sets the help text for this parameter.- Parameters:
help
- the help text for this parameter.
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