ArgReader.java

package org.nocket.util;

import java.util.Hashtable;

/**
 * This class emulates the good old UNIX command line argument reader functions.
 * 
 * @author <a href="mailto:jlessner@gmx.de">Jan Lessner</a>
 */
public class ArgReader {

	public static final char ARGEND = 0;
	public static final char ARGERROR = '$';
	public static final char COLON = ':';
	public static final String COLON_STRING = COLON + "";
	public static final String DASH_STRING = "-";

	private Hashtable<String, String> supportedArgs;
	private String[] args;
	private String argValue = null;
	private int argNo = 0;

	public ArgReader(String[] args, String argpattern) {
		this.args = args;
		this.supportedArgs = new Hashtable<String, String>();

		for (int i = 0; i < argpattern.length() - 1; i++) {
			if (argpattern.charAt(i) != COLON) {
				supportedArgs.put(String.valueOf(argpattern.charAt(i)), (argpattern.charAt(i + 1) == COLON) ? COLON_STRING : " ");
			}
		}
	}

	public char getArg() {
		try {

			char result = ARGEND;
			boolean flag = false;

			if (argNo < args.length) {
				if (args[argNo].startsWith(DASH_STRING)) {
					if (supportedArgs.get(String.valueOf(args[argNo].charAt(1))) != null) {
						if (supportedArgs.get(String.valueOf(args[argNo].charAt(1))).equals(COLON_STRING)) {
							if (args[argNo].length() > 2) {
								argValue = args[argNo].substring(2);
								args[argNo] = DASH_STRING + args[argNo].charAt(1);
								flag = false;
							} else {
								argValue = args[argNo + 1];
								flag = true;
							}
						} else {
							argValue = null;
						}
						result = args[argNo].charAt(1);

						if (args[argNo].length() > 2) {
							args[argNo] = DASH_STRING + args[argNo].substring(2);
						} else {
							if (flag == true) {
								argNo++;
							}
							argNo++;
						}
					} else {
						throw new IllegalArgumentException("No valid Argument: " + args[argNo].charAt(1));
					}
				} else {
					result = ARGEND;
				}
			} else {
				result = ARGEND;
			}
			return result;
		} catch (Exception ex) {
			throw new IllegalArgumentException("Parameter is missing");
		}
	}

	public String getArgValue() {
		return argValue;
	}

	public String[] getPendingArgs() {

		String[] pendingargs = new String[args.length - argNo];

		int l = 0;

		for (int i = argNo; i < args.length; i++) {
			pendingargs[l++] = args[i];
		}
		return pendingargs;
	}
}