com.globalmentor.application

Class CommandLineArguments

java.lang.Object

com.globalmentor.application.CommandLineArguments

public class CommandLineArguments
extends Object

Constants and utilities for accessing command-line arguments.

This implementation recognizes two types of command-line switches: options, which have arguments, and flags, which do not.

This implementation only recognizes long switches prefixed with "--".

Because MS-DOS batch files substitute a space for the equals sign, this implementation accepts the colon character (':') as a replacement for the equals sign ('=') in options, although the equals sign is preferred when possible.

Author:

Garret Wilson

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	CommandLineArguments.Switch Common command-line parameters.

Field Summary

Fields

Modifier and Type	Field and Description
static Pattern	FLAG_PATTERN The pattern for matching flags.
static String	LONG_SWITCH_DELIMITER The long delimiter that introduces a switch.
static Pattern	OPTION_PATTERN The pattern for matching options.
static Pattern	SWITCH_PATTERN The pattern for matching switches in general.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	CommandLineArguments() This class can only be instantiated if a class is derived from it.

Method Summary

Modifier and Type	Method and Description
static void	configureLog(String[] arguments) Sets default program debugging based upon the presence of the "log" flag and the logging switches.
static String	createSwitch(String switchString) Deprecated.
static <O extends Enum<O> & com.globalmentor.lex.Identifier> String	getOption(String[] arguments, O option) Searches the given arguments for the last occurrence of a particular option.
static <O extends Enum<O> & com.globalmentor.lex.Identifier,V extends Enum<V> & com.globalmentor.lex.Identifier> V	getOption(String[] arguments, O option, Class<V> valueType) Searches the given arguments for the last occurrence of a particular option.
static String	getOption(String[] arguments, String optionName) Searches the given arguments for the last occurrence of a particular option.
static <V extends Enum<V> & com.globalmentor.lex.Identifier> V	getOption(String[] arguments, String optionName, Class<V> valueType) Searches the given arguments for the last occurrence of a particular option.
static <O extends Enum<O> & com.globalmentor.lex.Identifier> List<String>	getOptions(String[] arguments, O option) Returns the given arguments for all occurrences a particular option.
static List<String>	getOptions(String[] arguments, String optionName) Returns the given arguments for all occurrences a particular option.
static <F extends Enum<F> & com.globalmentor.lex.Identifier> boolean	hasFlag(String[] arguments, F flag) Searches the argument array to see if a particular flag is defined.
static boolean	hasFlag(String[] arguments, String flagName) Searches the argument array to see if a particular flag is defined.
static boolean	hasHelpFlag(String[] arguments) Returns whether the help flag is turned on.
static boolean	isSwitch(String argument) Checks to see if a particular argument is a switch, without regard to whether it is an option or a flag.

Methods inherited from class java.lang.Object

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

Field Detail

LONG_SWITCH_DELIMITER

public static final String LONG_SWITCH_DELIMITER

The long delimiter that introduces a switch.

See Also:

Constant Field Values

SWITCH_PATTERN

public static final Pattern SWITCH_PATTERN

The pattern for matching switches in general.

FLAG_PATTERN

public static final Pattern FLAG_PATTERN

The pattern for matching flags.

OPTION_PATTERN

public static final Pattern OPTION_PATTERN

The pattern for matching options.

Constructor Detail

CommandLineArguments

protected CommandLineArguments()

This class can only be instantiated if a class is derived from it.

Method Detail

configureLog

public static void configureLog(String[] arguments)

Sets default program debugging based upon the presence of the "log" flag and the logging switches.

Parameters:

arguments - The array of command line arguments.

See Also:

CommandLineArguments.Switch.LOG_LEVEL, CommandLineArguments.Switch.VERBOSE, CommandLineArguments.Switch.QUIET, CommandLineArguments.Switch.LOG_FILE

hasHelpFlag

public static boolean hasHelpFlag(String[] arguments)

Returns whether the help flag is turned on.

Parameters:

arguments - The array of command line arguments.

Returns:

true if the help flag is defined.

See Also:

CommandLineArguments.Switch.HELP

hasFlag

public static <F extends Enum<F> & com.globalmentor.lex.Identifier> boolean hasFlag(String[] arguments,
                                                                                    F flag)

Searches the argument array to see if a particular flag is defined.

This implementation delegates to #getFlag(String[], String) using the serialization form of the given enum.

Type Parameters:

F - The type of flag.

Parameters:

arguments - The array of command line arguments.

flag - The name of the flag which may be defined.

Returns:

true if the flag is defined, else false.

See Also:

Enums.getSerializationName(Enum), hasFlag(String[], String)

hasFlag

public static boolean hasFlag(String[] arguments,
                              String flagName)

Searches the argument array to see if a particular flag is defined.

Parameters:

arguments - The array of command line arguments.

flagName - The name of the flag which may be defined.

Returns:

true if the flag is defined, else false.

See Also:

FLAG_PATTERN

getOption

public static <O extends Enum<O> & com.globalmentor.lex.Identifier,V extends Enum<V> & com.globalmentor.lex.Identifier> V getOption(String[] arguments,
                                                                                                                                    O option,
                                                                                                                                    Class<V> valueType)

Searches the given arguments for the last occurrence of a particular option. Using the last occurrence allows options to be appended to an existing batch or shell file on the command line and override the defaults.

This implementation delegates to getOption(String[], String, Class) using the serialization form of the given enum.

Type Parameters:

O - The type of option.

V - The type of value.

Parameters:

arguments - The array of command line arguments.

option - The option.

valueType - The type of value to expect.

Returns:

The argument of the last occurrence of the given option, or null if the option is not defined.

Throws:

IllegalArgumentException - if the given value is not valid for the expected type.

See Also:

Enums.getSerializationName(Enum), Enums.getSerializedEnum(Class, String), getOption(String[], String, Class)

getOption

public static <O extends Enum<O> & com.globalmentor.lex.Identifier> String getOption(String[] arguments,
                                                                                     O option)

Searches the given arguments for the last occurrence of a particular option. Using the last occurrence allows options to be appended to an existing batch or shell file on the command line and override the defaults.

This implementation delegates to getOption(String[], String) using the serialization form of the given enum.

Type Parameters:

O - The type of option.

Parameters:

arguments - The array of command line arguments.

option - The option.

Returns:

The argument of the last occurrence of the given option, or null if the option is not defined.

See Also:

Enums.getSerializationName(Enum), getOption(String[], String)

getOption

public static <V extends Enum<V> & com.globalmentor.lex.Identifier> V getOption(String[] arguments,
                                                                                String optionName,
                                                                                Class<V> valueType)

Searches the given arguments for the last occurrence of a particular option. Using the last occurrence allows options to be appended to an existing batch or shell file on the command line and override the defaults.

This implementation converts the value, if any, to the given value type, interpreting the value as the serialized form of an enum.

Type Parameters:

V - The type of value.

Parameters:

arguments - The array of command line arguments.

optionName - The name of the option.

valueType - The type of value to expect.

Returns:

The argument of the last occurrence of the given option, or null if the option is not defined.

Throws:

IllegalArgumentException - if the given value is not valid for the expected type.

See Also:

OPTION_PATTERN, Enums.getSerializedEnum(Class, String)

getOption

public static String getOption(String[] arguments,
                               String optionName)

Searches the given arguments for the last occurrence of a particular option. Using the last occurrence allows options to be appended to an existing batch or shell file on the command line and override the defaults.

Parameters:

arguments - The array of command line arguments.

optionName - The name of the option.

Returns:

The argument of the last occurrence of the given option, or null if the option is not defined.

See Also:

OPTION_PATTERN

getOptions

public static <O extends Enum<O> & com.globalmentor.lex.Identifier> List<String> getOptions(String[] arguments,
                                                                                            O option)

Returns the given arguments for all occurrences a particular option.

This implementation delegates to getOptions(String[], String) using the serialization form of the given enum.

Parameters:

arguments - The array of command line arguments.

option - The option.

Returns:

A non-null list of arguments of the defined options, if any, in the order encountered.

See Also:

Enums.getSerializationName(Enum), getOptions(String[], String)

getOptions

public static List<String> getOptions(String[] arguments,
                                      String optionName)

Returns the given arguments for all occurrences a particular option.

Parameters:

arguments - The array of command line arguments.

optionName - The name of the option.

Returns:

A non-null list of arguments of the defined options, if any, in the order encountered.

See Also:

OPTION_PATTERN

isSwitch

public static boolean isSwitch(String argument)

Checks to see if a particular argument is a switch, without regard to whether it is an option or a flag.

Parameters:

argument - The argument to check.

Returns:

true if the argument is a switch.

See Also:

SWITCH_PATTERN

createSwitch

@Deprecated
public static String createSwitch(String switchString)

Deprecated.

Creates a switch argument in the form -switchString.

Parameters:

switchString - The string to make into a switch.

Returns:

A command-line switch.