If you want to minimize the amount of code handling the command
line, JSAP offers a SimpleJSAP that does most of
the work for you. An instance of SimpleJSAP works
much like an instance of JSAP, but it accepts a
command name, a command explanation, and an array of
Parameter objects (there are several constructors
that should cover most of the common cases, but you can also
chain-invoke setters). If parsing fails for any reason, or if
--help is specified, the user is fully informed, and
the method messagePrinted() will return true.
public static void main(String[] args) throws Exception {
SimpleJSAP jsap = new SimpleJSAP(
"MyProgram",
"Repeats \"Hello, world!\" multiple times",
new Parameter[] {
new FlaggedOption( "count", JSAP.INTEGER_PARSER, "1", JSAP.REQUIRED, 'n', JSAP.NO_LONGFLAG,
"The number of times to say hello." ),
new QualifiedSwitch( "verbose", JSAP.STRING_PARSER, JSAP.NO_DEFAULT, JSAP.NOT_REQUIRED, 'v', "verbose",
"Requests verbose output." ).setList( true ).setListSeparator( ',' ),
new UnflaggedOption( "name", JSAP.STRING_PARSER, "World", JSAP.REQUIRED, JSAP.GREEDY,
"One or more names of people you would like to greet." )
}
);
JSAPResult config = jsap.parse(args);
if ( jsap.messagePrinted() ) System.exit( 1 );
String[] names = config.getStringArray("name");
String[] languages = config.getStringArray("verbose");
for (int i = 0; i < languages.length; ++i) {
System.out.println("language=" + languages[i]);
}
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]$java com.martiansoftware.jsap.examples.Manual_HelloWorld_Simple -n 2 --verbose ZoidbergHello, Zoidberg! Hello, Zoidberg![mlamb@morbo]$java com.martiansoftware.jsap.examples.Manual_HelloWorld_Simple --verbose:de Farnsworthlanguage=de Hello, Farnsworth![mlamb@morbo]$java com.martiansoftware.jsap.examples.Manual_HelloWorld_Simple -v:de,en Braniganlanguage=de language=en Hello, Branigan![mlamb@morbo]$java com.martiansoftware.jsap.examples.Manual_HelloWorld_Simple Horrible_Gelatanous_BlobHi, Horrible_Gelatanous_Blob![mlamb@morbo]$java com.martiansoftware.jsap.examples.Manual_HelloWorld_Simple --helpUsage: MyProgram [--help] -n <count> [(-v|--verbose)[:verbose1,verbose2,...,verboseN ]] name1 name2 ... nameN Repeats "Hello, world!" multiple times [--help] Prints this help message. -n <count> The number of times to say hello. (default: 1) [(-v|--verbose)[:verbose1,verbose2,...,verboseN ]] Requests verbose output. name1 name2 ... nameN One or more names of people you would like to greet. (default: World)