org.molgenis.util.cmdline

Class CmdLineParser

java.lang.Object

org.molgenis.util.cmdline.CmdLineParser

public class CmdLineParser
extends Object

This class defines the commandline options parser. Based on a class filled with members annotated with the Option annotation-type the parser knows for which minus parameters to look and to convert the accompanying string to which type. After the parse-function is finished the annotated object is filled with the data passed with the command-line options.

   class Example
   {
      class Options
      {
         \@Option(name="t", param="integer", type=Option.OptionType.REQUIRED_ARGUMENT, usage=
                "a long description here ...")
         public int threshold = 500;
         
         \@option(name="f", param="filename", type=Option.OptionType.REQUIRED_ARGUMENT, usage=
                "a long description here ...")
         public String file = "std_file.txt";
         
         \@option(name="fs", param="filename-list comma separated", type=Option.OptionType.REQUIRED_ARGUMENT, usage=
                "a long description here ...")
         public Vector files = new Vector();
         
         \@option(name="d", param="", type=Option.OptionType.NO_ARGUMENT, usage=
                "a long description here ...")
         public boolean do_something = false; 
      }
      
      public static void main(String args[])
      {
         Example m = new Example();
         Options options = m.new Options();
         CmdLineParser parser = new CmdLineParser(options);
         
         try
         {
            parser.parse(args);
         }
         catch(CmdLineException e)
         {
            parser.printUsage(System.err, e.toString());
         }
         
         if (options.do_something)
         {
            ...
         }
      }
   }
 

TODO Although some support is in place, methods are still not supported. TODO Help-output should be nicely formatted. TODO Make the program description also an annotated type ?

Version:

1.0.0

Author:

RA Scheltema

Constructor Summary

Constructors

Constructor and Description
CmdLineParser(Object options) Standard constructor where the options-object and the description are set.

Method Summary

Modifier and Type	Method and Description
void	parse(Properties properties) With this function the parser is invoked for the properties.
void	parse(String[] args) With this function the parser is invoked for the command-line options.
void	printOptions()
void	printUsage(PrintStream stream, String msg) With this method the usage description can be printed to a print-stream.
String	toString(Object options) Pretty print the options.

Methods inherited from class java.lang.Object

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

Constructor Detail

CmdLineParser

public CmdLineParser(Object options)
              throws NullPointerException,
                     CmdLineException

Standard constructor where the options-object and the description are set. The options-object is parsed for annotated variables and functions, which are saved for the parse-function. After successful completion of this constructor, the parse-function has the information it needs to deal with the command-line options.

Parameters:

o - The options-object with the annotated variables and functions.

description - The program description. throws NullPointerException When either of the parameters has been set to null.

Throws:

CmdLineException

NullPointerException

Method Detail

parse

public void parse(String[] args)
           throws CmdLineException

With this function the parser is invoked for the command-line options. The parser looks for -option entries in the command-line options and tries to translate the information into the annotated object. After successful completion of this method, the annotated object set in the constructor will contain all the information found in the command-line options.

Parameters:

args - The command-line options.

Throws:

CmdLineException - When the options cannot be parsed due to insufficient number, etc..

parse

public void parse(Properties properties)
           throws CmdLineException

With this function the parser is invoked for the properties. The parser looks for entries in the properties list and tries to translate the information into the annotated object. After successful completion of this method, the annotated object set in the constructor will contain all the information found in the command-line options.

Parameters:

properties - the properties set

Throws:

CmdLineException - When the options cannot be parsed due to insufficient number, etc..

printOptions

public void printOptions()

printUsage

public void printUsage(PrintStream stream,
                       String msg)

With this method the usage description can be printed to a print-stream. The output will be formatted to look good on a 80 characters wide display (typical for a command-line prompt).

Parameters:

stream - The print-stream to write the information to.

msg - The extra message (when needed) that will be displayed above the usage.

toString

public String toString(Object options)
                throws CmdLineException

Pretty print the options. Uses reflection to filter out the relevant fields.

Throws:

CmdLineException