com.easy.argparse

Class ArgumentParser

java.lang.Object

com.easy.argparse.ArgumentParser

public class ArgumentParser
extends Object

This thread-safe class parses the command line arguments provided in form of an array of Strings and instantiates data class such that parsed values can be obtained from the created instance of data class
For example, consider below:
Expected format: -m minute [-s seconds]
Command line arguments: -s 45 -m 20
Then, created instance of data class can be used to obtain 20 for minute and 45 for seconds
Follow below rules to use this class:

• Usage expression (like -m minute [-s seconds] can contain as many mandatory and optional expressions as required but optional expressions cannot be nested
• Any other bracket (curly braces or round brackets) must not be present in usage format expression
• A variable with name same as specified in usage expression must be present in the data class, along with corresponding setter method
• The data type of variable corresponding to name in usage expression must be either of below:
  
  1. String
  2. Primitive data type (boolean, byte, char, short, int, long, float, double)
  3. Wrapper to primitive data type (Boolean, Byte, Character, Short, Integer, Long, Float, Double)
  4. An array of any of the above types
• An optional alias can be defined. For example, -m|--min minute is a valid usage expression and -m or --min can be used in corresponding command line arguments
• The delimiter to identify different elements of an array can be any valid String
• Usage expression is case sensitive
• All options except those corresponding to boolean type except a value to be specified in the command line arguments
• If anything is wrong, e.g. usage expression is not valid etc., then an IllegalArgumentException with appropriate message will be thrown

Author:

himanshu_shekhar

Constructor Summary

Constructors

Constructor and Description
ArgumentParser(String usageExpression, Class<?> dataHolderClass)
ArgumentParser(String usageExpression, Class<?> dataHolderClass, String arrayDelimiter)

Method Summary

Modifier and Type	Method and Description
Object	parse(String[] args)

Methods inherited from class java.lang.Object

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

Constructor Detail

ArgumentParser

public ArgumentParser(String usageExpression,
                      Class<?> dataHolderClass)

Parameters:

usageExpression - The expression representing format in which command line arguments will be specified For example: --min|-m minute [--sec|-s seconds]

dataHolderClass - The class which will contain the values specified in command line arguments. This class must have variables specified in the usageExpression, corresponding setterMethod and default constructor For example: if usageExpression is --min|-m minute [--sec|-s seconds], the dataHolderClass must have minute and seconds as variables and setMinute and setSeconds methods and default constructor

ArgumentParser

public ArgumentParser(String usageExpression,
                      Class<?> dataHolderClass,
                      String arrayDelimiter)

Parameters:

usageExpression - As described above

dataHolderClass - As described above

arrayDelimiter - The delimiter text which will be used to determine the array specified in command line argument

Method Detail

parse

public Object parse(String[] args)

Parameters:

args - The values representing command line arguments (or any String array for that sake)

Returns:

A new instance of dataHolderClass specified in constructor with values available in args set appropriately