common.cmdline
Class BooleanOption

java.lang.Object
  common.cmdline.AbstractOption
      common.cmdline.BooleanOption

All Implemented Interfaces:

Option

public class BooleanOption
extends AbstractOption

Option that takes Boolean values. A Boolean option does not expect any value on the command line, but it can have two long forms, one indicating that the value is true and one indicating that it's false. If a Boolean option occurs more than once on a command line, this class prints a warning and ignores all but the last occurrence.

Field Summary

Fields inherited from class common.cmdline.AbstractOption

DOC_OFFSET, longForms, occurred, shortForms

Constructor Summary

BooleanOption(java.lang.String shortForm, java.lang.String longForm, boolean def, java.lang.String docStr)
Creates a Boolean option and registers it with the Parser class.

Method Summary

boolean	expectsValue() Returns true if this option expects a value on the command line.
java.lang.String	getUsageString() Returns a string that documents the option.
boolean	getValue() Returns the value specified on the command line for this option, or the default value if the option did not occur.
void	recordOccurrence(java.lang.String form, java.lang.String valueStr) This default implementation prints a warning if this option has already been occurred.

Methods inherited from class common.cmdline.AbstractOption

getLongForms, getShortForms, toString, wasPresent

Methods inherited from class java.lang.Object

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

Constructor Detail

BooleanOption

public BooleanOption(java.lang.String shortForm,
                     java.lang.String longForm,
                     boolean def,
                     java.lang.String docStr)

Creates a Boolean option and registers it with the Parser class.

Parameters:

shortForm - single-character flag indicating that the value is true, or null for an option with no short form

longForm - long form indicating that the value is true, or null for an option with no long form. If a long form foo is specified, then a second long form nofoo is also defined to indicate that the option value is false.

def - default value to return if the option does not occur

docStr - short (preferably less than 40 characters) string specifying what happens when this option is true

Method Detail

expectsValue

public boolean expectsValue()

Description copied from interface: Option

Returns true if this option expects a value on the command line.

recordOccurrence

public void recordOccurrence(java.lang.String form,
                             java.lang.String valueStr)

Description copied from class: AbstractOption

This default implementation prints a warning if this option has already been occurred. It also sets the occurred member variable to true. However, it does not parse or record the value.

Specified by:

recordOccurrence in interface Option

Overrides:

recordOccurrence in class AbstractOption

Parameters:

form - specifies the particular long or short form of the option that was used

valueStr - the given value, or null if no value was given. The parser will only pass null for this parameter if expectsValue returns false; otherwise, if the value is missing, the parser will not call this method.

getUsageString

public java.lang.String getUsageString()

Description copied from interface: Option

Returns a string that documents the option. This string should fit on one 80-column line.

getValue

public boolean getValue()

Returns the value specified on the command line for this option, or the default value if the option did not occur.