Here you can find the source of unsignedExtend(String hex)
static String unsignedExtend(String hex)
//package com.java2s; /*//from w w w . j a v a 2 s . co m * Copyright (c) 2013, 2017, 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. */ public class Main { static final int SIZE_OF_LONG_HEX = 16; static String unsignedExtend(String hex) { int numOfMissingHexDigit = SIZE_OF_LONG_HEX - hex.length(); StringBuilder sb = new StringBuilder(); for (int i = 0; i < numOfMissingHexDigit; i++) { sb.append('0'); } return sb.append(hex).toString(); } }