Here you can find the source of zeropad(String s, int len)
| Parameter | Description |
|---|---|
| s | - original string |
| len | - desired len |
public static String zeropad(String s, int len) throws Exception
//package com.java2s; /*//from ww w . j av a 2s. c om * Copyright (c) 2000 jPOS.org. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. The end-user documentation included with the redistribution, * if any, must include the following acknowledgment: * "This product includes software developed by the jPOS project * (http://www.jpos.org/)". Alternately, this acknowledgment may * appear in the software itself, if and wherever such third-party * acknowledgments normally appear. * * 4. The names "jPOS" and "jPOS.org" must not be used to endorse * or promote products derived from this software without prior * written permission. For written permission, please contact * license@jpos.org. * * 5. Products derived from this software may not be called "jPOS", * nor may "jPOS" appear in their name, without prior written * permission of the jPOS project. * * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE JPOS PROJECT OR ITS CONTRIBUTORS BE LIABLE FOR * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * ==================================================================== * * This software consists of voluntary contributions made by many * individuals on behalf of the jPOS Project. For more * information please see <http://www.jpos.org/>. */ public class Main { /** * left pad with '0' * @param s - original string * @param len - desired len * @return zero padded string */ public static String zeropad(String s, int len) throws Exception { return padleft(s, len, '0'); } /** * pad to the left * @param s - original string * @param len - desired len * @param c - padding char * @return padded string */ public static String padleft(String s, int len, char c) throws Exception { s = s.trim(); if (s.length() > len) throw new Exception("invalid len " + s.length() + "/" + len); StringBuffer d = new StringBuffer(len); int fill = len - s.length(); while (fill-- > 0) d.append(c); d.append(s); return d.toString(); } /** * trim String (if not null) * @param s String to trim * @return String (may be null) */ public static String trim(String s) { return s != null ? s.trim() : null; } /** * Trims a byte[] to a certain length * @param array the byte[] to be trimmed * @param length the wanted length * @return the trimmed byte[] */ public static byte[] trim(byte[] array, int length) { byte[] trimmedArray = new byte[length]; System.arraycopy(array, 0, trimmedArray, 0, length); return trimmedArray; } }