/*
 * Copyright (c) 2001 Matthew Feldt. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided the copyright notice above is
 * retained.
 *
 * THIS SOFTWARE IS PROVIDED ''AS IS'' AND WITHOUT ANY EXPRESSED OR
 * IMPLIED WARRANTIES.
 */

/**
 * Substring.java
 *
 * Java Examples In A Nutshell Copyright (c) 2000 David Flanagan
 * Exercise 1-3:
 * Write a program that takes two numbers and a string as command-line
 * arguments and prints out the substring of the string specified by the
 * two numbers.
 *
 * For example:
 * % java Substring hello 1 3
 *
 * should print out:
 * ell
 *
 * Handle all possible exceptions that might arise because of bad input.
 *
 * @author Matthew Feldt <developer@feldt.com>
 * @version 1.0, 01/27/2001 16:02
 */

package com.feldt.examples.basics;

public class Substring {
	public static void main (String args[]) {
		final String usage = "Usage: java Substring string beginIndex endIndex";
		int beginIndex, endIndex;

		// confirm the right number of command-line arguments
		if (args.length != 3) {
			System.err.println(usage);
			System.exit(-1);
		}

		try { // parse beginIndex and endIndex
			beginIndex = Integer.parseInt(args[1]);
			endIndex = Integer.parseInt(args[2]);

			// check for valid input
			if (beginIndex < 0)
				throw new NumberFormatException("beginIndex (" + beginIndex +
					") must be greater than or equal 0.");

			if (beginIndex > endIndex)
				throw new NumberFormatException("beginIndex (" + beginIndex +
					") must be less than endIndex (" + endIndex + ").");

			if (! (endIndex < args[0].length()))
				throw new NumberFormatException("endIndex (" + endIndex +
					") must be less than string length (" + args[0].length() + ").");

			// increment endIndex so String.substring() will include endIndex
			endIndex++;

			// print the substring bounded by beginIndex and endIndex
			System.out.println(args[0].substring(beginIndex, endIndex));
		} catch(NumberFormatException e) {
			System.err.println(e);
		}
	}
}