Apache Commons CLI - Properties Option

Overview

A Properties option is represented on a command line by its name and its corresponding properties like syntax, which is similar to java properties file. Consider the following example, if we are passing options like -DrollNo = 1 -Dclass = VI -Dname = Mahesh, we should process each value as properties.

java CLITester -DrollNo=1 -Dclass=VI -Dname=Mahesh

Then

• rollNo should 1

• class as VI

• name as Mahesh

Define the Option as Properties Option

Option propertyOption = Option.builder()
         .longOpt("D")
         .argName("property=value" )
         .hasArgs()
         .valueSeparator()
         .numberOfArgs(2)
         .desc("use value for given properties" )
         .get();

Read properties using getOptionProperties() method

if(cmd.hasOption("D")) {
   Properties properties = cmd.getOptionProperties("D");
   System.out.println("Class: " + properties.getProperty("class"));
   System.out.println("Roll No: " + properties.getProperty("rollNo"));
   System.out.println("Name: " + properties.getProperty("name"));
}

Example - Reading Arguments as Properties based on Option passed

In this example, we're process each value passed as properties.

CLITester.java

package com.tutorialspoint;

import java.util.Properties;

import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.CommandLineParser;
import org.apache.commons.cli.DefaultParser;
import org.apache.commons.cli.Option;
import org.apache.commons.cli.Options;
import org.apache.commons.cli.ParseException;

public class CLITester {
   public static void main(String[] args) throws ParseException {
      Options options = new Options();
      Option propertyOption = Option.builder()
         .longOpt("D")
         .argName("property=value" )
         .hasArgs()
         .valueSeparator()
         .numberOfArgs(2)
         .desc("use value for given properties" )
         .get();
      
      options.addOption(propertyOption);
      CommandLineParser parser = new DefaultParser();
      CommandLine cmd = parser.parse( options, args);
      
      if(cmd.hasOption("D")) {
         Properties properties = cmd.getOptionProperties("D");
         System.out.println("Class: " + properties.getProperty("class"));
         System.out.println("Roll No: " + properties.getProperty("rollNo"));
         System.out.println("Name: " + properties.getProperty("name"));
      }
   }
}

Output

Run the file, while passing options as key value pairs and see the result −

java CLITester -DrollNo=1 -Dclass=VI -Dname=Mahesh
Class: VI
Roll No: 1
Name: Mahesh