Here you can find the source of longToHexString(long n, int digits)
public static String longToHexString(long n, int digits)
//package com.java2s; /*//from w w w. j a v a 2 s.c om This file belongs to the Servoy development and deployment environment, Copyright (C) 1997-2010 Servoy BV This program is free software; you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. This program 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 Affero General Public License for more details. You should have received a copy of the GNU Affero General Public License along with this program; if not, see http://www.gnu.org/licenses or write to the Free Software Foundation,Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 */ public class Main { public static String longToHexString(long n, int digits) { StringBuilder buffer = new StringBuilder(Long.toHexString(n)); if (buffer.length() > digits) return buffer.substring(buffer.length() - digits); while (buffer.length() < digits) buffer.insert(0, '0'); return buffer.toString(); } }