Java example source code file (ASCIIUtility.java)

This example Java source code file (ASCIIUtility.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

asciiutility, byteoutputstream, ioexception, numberformatexception, only, string

The ASCIIUtility.java Java example source code

/*
 * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

/*
 * @(#)ASCIIUtility.java      1.9 02/03/27
 */


package com.sun.xml.internal.messaging.saaj.packaging.mime.util;

import com.sun.xml.internal.messaging.saaj.util.ByteOutputStream;

import java.io.*;

public class ASCIIUtility {

    // Private constructor so that this class is not instantiated
    private ASCIIUtility() { }


    /**
     * Convert the bytes within the specified range of the given byte
     * array into a signed integer in the given radix . The range extends
     * from <code>start till, but not including end. 

     *
     * Based on java.lang.Integer.parseInt()
     */
    public static int parseInt(byte[] b, int start, int end, int radix)
                throws NumberFormatException {
        if (b == null)
            throw new NumberFormatException("null");

        int result = 0;
        boolean negative = false;
        int i = start;
        int limit;
        int multmin;
        int digit;

        if (end > start) {
            if (b[i] == '-') {
                negative = true;
                limit = Integer.MIN_VALUE;
                i++;
            } else {
                limit = -Integer.MAX_VALUE;
            }
            multmin = limit / radix;
            if (i < end) {
                digit = Character.digit((char)b[i++], radix);
                if (digit < 0) {
                    throw new NumberFormatException(
                        "illegal number: " + toString(b, start, end)
                        );
                } else {
                    result = -digit;
                }
            }
            while (i < end) {
                // Accumulating negatively avoids surprises near MAX_VALUE
                digit = Character.digit((char)b[i++], radix);
                if (digit < 0) {
                    throw new NumberFormatException("illegal number");
                }
                if (result < multmin) {
                    throw new NumberFormatException("illegal number");
                }
                result *= radix;
                if (result < limit + digit) {
                    throw new NumberFormatException("illegal number");
                }
                result -= digit;
            }
        } else {
            throw new NumberFormatException("illegal number");
        }
        if (negative) {
            if (i > start + 1) {
                return result;
            } else {    /* Only got "-" */
                throw new NumberFormatException("illegal number");
            }
        } else {
            return -result;
        }
    }

    /**
     * Convert the bytes within the specified range of the given byte
     * array into a String. The range extends from <code>start
     * till, but not including <code>end. 

     */
    public static String toString(byte[] b, int start, int end) {
        int size = end - start;
        char[] theChars = new char[size];

        for (int i = 0, j = start; i < size; )
            theChars[i++] = (char)(b[j++]&0xff);

        return new String(theChars);
    }

    public static byte[] getBytes(String s) {
        char [] chars= s.toCharArray();
        int size = chars.length;
        byte[] bytes = new byte[size];

        for (int i = 0; i < size;)
            bytes[i] = (byte) chars[i++];
        return bytes;
    }

    /**
     *
     * @deprecated
     *      this is an expensive operation that require an additional
     *      buffer reallocation just to get the array of an exact size.
     *      Unless you absolutely need the exact size array, don't use this.
     *      Use {@link ByteOutputStream} and {@link ByteOutputStream#write(InputStream)}.
     */
    public static byte[] getBytes(InputStream is) throws IOException {
        ByteOutputStream bos = new ByteOutputStream();
        try {
            bos.write(is);
        } finally {
            is.close();
        }
        return bos.toByteArray();
    }
}