How do I parse command line arguments in Java?

Check these out:

• http://commons.apache.org/cli/
• http://www.martiansoftware.com/jsap/

Or roll your own:

• http://docs.oracle.com/javase/7/docs/api/java/util/Scanner.html

For instance, this is how you use commons-cli to parse 2 string arguments:

import org.apache.commons.cli.*;public class Main {    public static void main(String[] args) throws Exception {        Options options = new Options();        Option input = new Option("i", "input", true, "input file path");        input.setRequired(true);        options.addOption(input);        Option output = new Option("o", "output", true, "output file");        output.setRequired(true);        options.addOption(output);        CommandLineParser parser = new DefaultParser();        HelpFormatter formatter = new HelpFormatter();        CommandLine cmd = null;//not a good practice, it serves it purpose         try {            cmd = parser.parse(options, args);        } catch (ParseException e) {            System.out.println(e.getMessage());            formatter.printHelp("utility-name", options);            System.exit(1);        }        String inputFilePath = cmd.getOptionValue("input");        String outputFilePath = cmd.getOptionValue("output");        System.out.println(inputFilePath);        System.out.println(outputFilePath);    }}

usage from command line:

$> java -jar target/my-utility.jar -i asd                                                                                       Missing required option: ousage: utility-name -i,--input <arg>    input file path -o,--output <arg>   output file

Take a look at the more recent JCommander.

I created it. I’m happy to receive questions or feature requests.

I have been trying to maintain a list of Java CLI parsers.

• Airline
  • Active Fork: https://github.com/rvesse/airline
• argparse4j
• argparser
• args4j
• clajr
• cli-parser
• CmdLn
• Commandline
• DocOpt.java
• dolphin getopt
• DPML CLI (Jakarta Commons CLI2 fork)
• Dr. Matthias Laux
• Jakarta Commons CLI
• jargo
• jargp
• jargs
• java-getopt
• jbock
• JCLAP
• jcmdline
• jcommander
• jcommando
• jewelcli (written by me)
• JOpt simple
• jsap
• naturalcli
• Object Mentor CLI article (more about refactoring and TDD)
• parse-cmd
• ritopt
• Rop
• TE-Code Command
• picocli has ANSI colorized usage help and autocomplete