JSAP jsap = new JSAP(); FlaggedOption opt = new FlaggedOption("input") .setStringParser(JSAP.STRING_PARSER) .setDefault("defaultInput") .setList(false) .setRequired(true) .setShortFlag('i') .setLongFlag(JSAP.NO_LONGFLAG); jsap.registerParameter(opt); JSAPResult jsapResult = jsap.parse(args); JSAP jsap = new JSAP(); jsap.setUsage("java yourprogram"); jsap.setErrorPrintStream(System.err); jsap.setHelp("program options"); import com.martiansoftware.jsap.FlaggedOption; import com.martiansoftware.jsap.JSAP; import com.martiansoftware.jsap.JSAPException; import com.martiansoftware.jsap.JSAPResult; import com.martiansoftware.jsap.UnflaggedOption; public class CommandTool { public static void main(String[] args) throws JSAPException { JSAP jsap = new JSAP(); FlaggedOption inputOpt = new FlaggedOption("input") .setStringParser(JSAP.STRING_PARSER) .setDefault("defaultInput") .setList(false) .setRequired(true) .setShortFlag('i') .setLongFlag(JSAP.NO_LONGFLAG); jsap.registerParameter(inputOpt); UnflaggedOption outputOpt = new UnflaggedOption("output") .setStringParser(JSAP.STRING_PARSER) .setDefault("defaultOutput") .setList(false) .setRequired(true) .setGreedy(false); jsap.registerParameter(outputOpt); JSAPResult jsapResult = jsap.parse(args); if (!jsapResult.success()) { System.err.println("Invalid command line arguments. Please check the documentation or use --help for usage information."); System.err.println(jsap.getUsage()); System.exit(1); } \t\tString input = jsapResult.getString("input"); String output = jsapResult.getString("output"); System.out.println("Input file: " + input); System.out.println("Output file: " + output); } }