org.snmp4j.util

Class ArgumentParser

java.lang.Object

org.snmp4j.util.ArgumentParser

public class ArgumentParser
extends Object

The ArgumentParser parsers a command line array into Java objects and associates each object with the corresponding command line option according to predefined schemes for options and parameters.

The format specification for options is:

 [-<option>\[<type>[\<<regex>\>]{<parameter>[=<default>]}\]] ...
 

where

• '-' indicates a mandatory option ('+' would indicate an optional option)
• <option> is the name of the option, for example 'h' for 'help'
• <type> is one of 'i' (integer), 'l' (long), 'o' (octet string), and 's' (string)
• <regex> is a regular expression pattern that describes valid values
• <default> is a default value. If a default value is given, then a mandatory option is in fact optional

The format specification for parameters is:

 [-<parameter>[<type>[<<regex>>]{[=<default>]}]]... [+<optionalParameter>[<type>[<<regex>>]{[=<default>]}]]... [<..>]
 

where

• '-' indicates a mandatory parameter whereas '+' would indicate an optional parameter which must not be followed by a mandatory parameter
• <parameter> is the name of the parameter, for example 'port'
• <type> is one of 'i' (integer), 'l' (long), and 's' (string)
• <regex> is a regular expression pattern that describes valid values
• <default> is a default value
• <..> (two consecutive dots after a space at the end of the pattern) indicate that the last parameter may occur more than once

Since:

1.9

Version:

1.10

Author:

Frank Fock

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ArgumentParser.ArgumentFormat
static class	ArgumentParser.ArgumentParameter
static class	ArgumentParser.ArgumentParseException

Field Summary

Fields

Modifier and Type	Field and Description
static int	TYPE_INTEGER
static int	TYPE_LONG
static int	TYPE_OCTET_STRING
static int	TYPE_STRING
static String[]	TYPES

Constructor Summary

Constructors

Constructor and Description
ArgumentParser(String optionFormat, String parameterFormat) Creates an argument parser with the specified option and parameter formats.

Method Summary

Modifier and Type	Method and Description
protected void	addValues2Option(String option, List values, Map<String,List<?>> options)
static Object	getFirstValue(List<? extends Object> optionValues) Gets the first option value of a list of values - if available.
Map<String,ArgumentParser.ArgumentFormat>	getOptionFormat()
Map<? extends String,? extends ArgumentParser.ArgumentFormat>	getParameterFormat()
static Object	getValue(Map args, String name, int index) Gets the n-th option value of a list of values - if available.
static void	main(String[] args) Test application to try out patterns and command line parameters.
Map<String,List<?>>	parse(String[] args) Parses the given command line and returns a map of parameter/option names to a List of values.
protected static Map<String,ArgumentParser.ArgumentFormat>	parseFormat(String format, boolean parameterFormat)
protected Object	parseParameterValue(ArgumentParser.ArgumentParameter type, String value, ArgumentParser.ArgumentFormat format, int pos)
protected List<?>	parseValues(String[] args, int offset, ArgumentParser.ArgumentFormat format)
static String[]	selectCommand(String[] args, String optionFormat, String[][] commandSets) Select a argument/parameter set from a given selection of sets by the command contained in the supplied argument list.

Methods inherited from class java.lang.Object

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

Field Detail

TYPES

public static final String[] TYPES

TYPE_INTEGER

public static final int TYPE_INTEGER

See Also:

Constant Field Values

TYPE_LONG

public static final int TYPE_LONG

See Also:

Constant Field Values

TYPE_STRING

public static final int TYPE_STRING

See Also:

Constant Field Values

TYPE_OCTET_STRING

public static final int TYPE_OCTET_STRING

See Also:

Constant Field Values

Constructor Detail

ArgumentParser

public ArgumentParser(String optionFormat,
                      String parameterFormat)

Creates an argument parser with the specified option and parameter formats.

Parameters:

optionFormat - the option format pattern to parse (see ArgumentParser).

parameterFormat - the parameter format pattern to parse (see ArgumentParser).

Method Detail

getOptionFormat

public Map<String,ArgumentParser.ArgumentFormat> getOptionFormat()

getParameterFormat

public Map<? extends String,? extends ArgumentParser.ArgumentFormat> getParameterFormat()

parseFormat

protected static Map<String,ArgumentParser.ArgumentFormat> parseFormat(String format,
                                                                       boolean parameterFormat)

parse

public Map<String,List<?>> parse(String[] args)
                          throws ParseException

Parses the given command line and returns a map of parameter/option names to a List of values. Each value may be of type Integer, Long, and String.

Parameters:

args - the command line argument list.

Returns:

Map a map that returns options and parameters in the order they have been parsed, where each map entry has the option/parameter name as key and the value as value.

Throws:

ParseException - if the command line does not match the patterns for options and parameters.

addValues2Option

protected void addValues2Option(String option,
                                List values,
                                Map<String,List<?>> options)

parseValues

protected List<?> parseValues(String[] args,
                              int offset,
                              ArgumentParser.ArgumentFormat format)
                       throws ParseException

Throws:

ParseException

parseParameterValue

protected Object parseParameterValue(ArgumentParser.ArgumentParameter type,
                                     String value,
                                     ArgumentParser.ArgumentFormat format,
                                     int pos)
                              throws ArgumentParser.ArgumentParseException

Throws:

ArgumentParser.ArgumentParseException

getFirstValue

public static Object getFirstValue(List<? extends Object> optionValues)

Gets the first option value of a list of values - if available.

Parameters:

optionValues - a probably empty list of values - could be null.

Returns:

the first option value in optionValues if it exists, null otherwise.

Since:

1.9.2

getValue

public static Object getValue(Map args,
                              String name,
                              int index)

Gets the n-th option value of a list of values - if available.

Parameters:

args - a parameter and options list.

name - the option or parameter name to return

index - the index (zero based) of the option/parameter value to return.

Returns:

the n-th (zero based) option value in args.get(name) if it exists, null otherwise.

Since:

1.10

main

public static void main(String[] args)

Test application to try out patterns and command line parameters. The default option and parameter patterns can be overridden by setting the system properties org.snmp4j.OptionFormat and org.snmp4j.ParameterFormat respectively.

The given command line is parsed using the specified patterns and the parsed values are returned on the console output.

The default option pattern is -o1[i{parameter1}] -o2[s,l] and the default parameter pattern is -param1[i] -param2[s<(udp|tcp):.*[/[0-9]+]?>] +optParam1[l{=-100}] ..

Parameters:

args - the command line arguments to match with the specified format patterns.

selectCommand

public static String[] selectCommand(String[] args,
                                     String optionFormat,
                                     String[][] commandSets)
                              throws ParseException

Select a argument/parameter set from a given selection of sets by the command contained in the supplied argument list. The command is the first argument not starting with "-".

Parameters:

args - the argument list to scan.

optionFormat - the option format which is common to all commands (or their super set)

commandSets - the possible command sets, where each set is identified by its command string in the first element of the command set.

Returns:

the command set matching the command in the argument list.

Throws:

ParseException - if the command found in args cannot be found in the commandSets, or null if args does not contain any command.

Since:

1.10