JArgs命令行选项解析>Java套件

项目简介和意图

这个小的工程是为java开发者提供的，使用命令行方便的，结构紧凑的解析器工具。

 

public class OptionTest {
	private static void printUsage() {
		System.err
				.println("Usage: OptionTest [-d,--debug] [{-v,--verbose}] [{--alt}] [{--name} a_name]\n"
						+ "                  [{-s,--size} a_number] [{-f,--fraction} a_float] [a_nother]");
	}

	public static void main(String[] args) {
		// First, you must create a CmdLineParser, and add to it the
		// appropriate Options.
		// To start with, we add the Options -d, -v, -s, and -f, with aliases
		// --debug, --verbose, --size, and --fraction respectively.
		// The -d and -v options have no associated value -- they are either
		// present, or they are not. The -s and -f options take integer and
		// double-precision floating-point values respectively.
		CmdLineParser parser = new CmdLineParser();
		CmdLineParser.Option debug = parser.addBooleanOption('d', "debug");
		CmdLineParser.Option verbose = parser.addBooleanOption('v', "verbose");
		CmdLineParser.Option size = parser.addIntegerOption('s', "size");
		CmdLineParser.Option fraction = parser.addDoubleOption('f', "fraction");

		// Options may have just a long form with no corresponding short form.
		// Here, we add --alt and --name options.
		CmdLineParser.Option alt = parser.addBooleanOption("alt");
		CmdLineParser.Option name = parser.addStringOption('n', "name");

		// Next, you must parse the user-provided command line arguments, and
		// catch any errors therein.
		// Options may appear on the command line in any order, and may even
		// appear after some or all of the non-option arguments.
		// If the user needs to specify non-option arguments that start with a
		// minus, then they may indicate the end of the parsable options with
		// -- , like this:
		// prog -f 20 -- -10 -fred
		// The -f 20 will be parsed as the fraction option, with the value 20.
		// The -10 and -fred arguments will be regarded as non-option
		// arguments, and passed through getRemainingArgs as unparsed Strings.
		// Short boolean options may be specified separately (-d -v) or
		// together (-dv).
		// Options with values may be given on the command line as -f 1.0 or
		// --fraction=1.0.
		try {
			parser.parse(args);
		} catch (CmdLineParser.OptionException e) {
			System.err.println(e.getMessage());
			printUsage();
			System.exit(2);
		}
		// For options that may be specified only zero or one time, the value
		// of that option may be extracted as shown below. If the options
		// were not specified, the corresponding values will be null.

		Boolean debugValue = (Boolean) parser.getOptionValue(debug);
		String nameValue = (String) parser.getOptionValue(name);
		// Alternatively, you may specify a default value. This will be
		// returned (instead of null) when the command line argument is
		// missing.

		Boolean altValue = (Boolean) parser.getOptionValue(alt, Boolean.FALSE);
		Integer sizeValue = (Integer) parser.getOptionValue(size, new Integer(
				42));

		// If your application requires it, options may be specified more than
		// once. In this case, you may get all the values specified by the
		// user, as a Vector:

		Vector fractionValues = parser.getOptionValues(fraction);

		// Alternatively, you may make the loop explicit:

		int verbosity = 0;
		while (true) {
			Boolean verboseValue = (Boolean) parser.getOptionValue(verbose);
			if (verboseValue == null) {
				break;
			} else {
				verbosity++;
			}
		}
		// The remaining command-line arguments -- those that do not start
		// with a minus sign -- can be captured like this:

		String[] otherArgs = parser.getRemainingArgs();

		// For testing purposes, we just print out the option values and
		// remaining command-line arguments. In a real program, of course,
		// one would pass them to a function that does something more useful.

		System.out.println("debug: " + debugValue);
		System.out.println("alt: " + altValue);
		System.out.println("size: " + sizeValue);
		System.out.println("name: " + nameValue);
		System.out.println("verbosity: " + verbosity);
		Enumeration e = fractionValues.elements();
		while (e.hasMoreElements()) {
			System.out.println("fraction: " + (Double) e.nextElement());
		}
		System.out.println("remaining args: ");
		for (int i = 0; i < otherArgs.length; ++i) {
			System.out.println(otherArgs[i]);
		}
		System.exit(0);
	}
}

 使用JArgs的项目有JBoss,Columba等。

 

总结一下就是这是一个java的命令解析的小的工程，可以方便的解析各种输入的参数信息。在YUICompressor项目中应用到了这个小的套件。