Here you can find the source of parseLong(byte[] b, int start, int end, int radix)
public static long parseLong(byte[] b, int start, int end, int radix) throws NumberFormatException
//package com.java2s; /*//from w w w .j a v a 2s. c o m * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER. * * Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved. * * The contents of this file are subject to the terms of either the GNU * General Public License Version 2 only ("GPL") or the Common Development * and Distribution License("CDDL") (collectively, the "License"). You * may not use this file except in compliance with the License. You can obtain * a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html * or glassfish/bootstrap/legal/LICENSE.txt. See the License for the specific * language governing permissions and limitations under the License. * * When distributing the software, include this License Header Notice in each * file and include the License file at glassfish/bootstrap/legal/LICENSE.txt. * Sun designates this particular file as subject to the "Classpath" exception * as provided by Sun in the GPL Version 2 section of the License file that * accompanied this code. If applicable, add the following below the License * Header, with the fields enclosed by brackets [] replaced by your own * identifying information: "Portions Copyrighted [year] * [name of copyright owner]" * * Contributor(s): * * If you wish your version of this file to be governed by only the CDDL or * only the GPL Version 2, indicate your decision by adding "[Contributor] * elects to include this software in this distribution under the [CDDL or GPL * Version 2] license." If you don't indicate a single choice of license, a * recipient has the option to distribute your version of this file under * either the CDDL, the GPL Version 2 or to extend the choice of license to * its licensees as provided above. However, if you add GPL Version 2 code * and therefore, elected the GPL Version 2 license, then the option applies * only if the new code is made subject to such option by the copyright * holder. */ import java.io.ByteArrayInputStream; public class Main { /** * Convert the bytes within the specified range of the given byte * array into a signed long in the given radix . The range extends * from <code>start</code> till, but not including <code>end</code>. <p> * * Based on java.lang.Long.parseLong() */ public static long parseLong(byte[] b, int start, int end, int radix) throws NumberFormatException { if (b == null) throw new NumberFormatException("null"); long result = 0; boolean negative = false; int i = start; long limit; long multmin; int digit; if (end > start) { if (b[i] == '-') { negative = true; limit = Long.MIN_VALUE; i++; } else { limit = -Long.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 signed long . The range extends from * <code>start</code> till, but not including <code>end</code>. <p> */ public static long parseLong(byte[] b, int start, int end) throws NumberFormatException { return parseLong(b, start, end, 10); } /** * Convert the bytes within the specified range of the given byte * array into a String. The range extends from <code>start</code> * till, but not including <code>end</code>. <p> */ 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 String toString(ByteArrayInputStream is) { int size = is.available(); char[] theChars = new char[size]; byte[] bytes = new byte[size]; is.read(bytes, 0, size); for (int i = 0; i < size;) theChars[i] = (char) (bytes[i++] & 0xff); return new String(theChars); } }