HelloWorld_7
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## HelloWorld_7

Showing the expected input of your program can be helpful, but it can be even more helpful to tell the user specifically what they did wrong. It's pretty easy as of version 1.03:

        public static void main(String[] args) throws Exception {
            JSAP jsap = new JSAP();

            FlaggedOption opt1 = new FlaggedOption("count")
                                    .setStringParser(JSAP.INTEGER_PARSER)
                                    .setDefault("1")
                                    .setRequired(true)
                                    .setShortFlag('n')
                                    .setLongFlag(JSAP.NO_LONGFLAG);

            opt1.setHelp("The number of times to say hello.");
            jsap.registerParameter(opt1);

            Switch sw1 = new Switch("verbose")
                            .setShortFlag('v')
                            .setLongFlag("verbose");

            sw1.setHelp("Requests verbose output.");
            jsap.registerParameter(sw1);

            UnflaggedOption opt2 = new UnflaggedOption("name")
                                    .setStringParser(JSAP.STRING_PARSER)
                                    .setDefault("World")
                                    .setRequired(true)
                                    .setGreedy(true);

            opt2.setHelp("One or more names of people you would like to greet.");
            jsap.registerParameter(opt2);

            JSAPResult config = jsap.parse(args);

            if (!config.success()) {

                System.err.println();

                // print out specific error messages describing the problems
                // with the command line, THEN print usage, THEN print full
                // help.  This is called "beating the user with a clue stick."
                for (java.util.Iterator errs = config.getErrorMessageIterator();
                        errs.hasNext();) {
                    System.err.println("Error: " + errs.next());
                }

                System.err.println();
                System.err.println("Usage: java "
                                    + Manual_HelloWorld_7.class.getName());
                System.err.println("                "
                                    + jsap.getUsage());
                System.err.println();
                System.err.println(jsap.getHelp());
                System.exit(1);
            }

            String[] names = config.getStringArray("name");
            for (int i = 0; i < config.getInt("count"); ++i) {
                for (int j = 0; j < names.length; ++j) {
                    System.out.println((config.getBoolean("verbose") ? "Hello" : "Hi")
                                    + ", "
                                    + names[j]
                                    + "!");
                }
            }
        }

    [mlamb@morbo]$ java com.martiansoftware.jsap.examples.Manual_HelloWorld_7 -n 2 -n 4

    Error: Parameter 'count' cannot be declared more than once.

    Usage: java com.martiansoftware.jsap.examples.Manual_HelloWorld_7
                    -n <count> [-v|--verbose] name1 name2 ... nameN

      -n <count>
            The number of times to say hello. (default: 1)

      [-v|--verbose]
            Requests verbose output.

      name1 name2 ... nameN
            One or more names of people you would like to greet. (default: World)

    [mlamb@morbo]$ java com.martiansoftware.jsap.examples.Manual_HelloWorld_7 --nosuchflag

    Error: Unknown flag 'nosuchflag'.

    Usage: java com.martiansoftware.jsap.examples.Manual_HelloWorld_7
                    -n <count> [-v|--verbose] name1 name2 ... nameN

      -n <count>
            The number of times to say hello. (default: 1)

      [-v|--verbose]
            Requests verbose output.

      name1 name2 ... nameN
            One or more names of people you would like to greet. (default: World)

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