Here you can find the source of substring(String origin, int len)
public static String substring(String origin, int len)
//package com.java2s; /*/* w ww. j a va2 s. c o m*/ * $Id: StringUtil.java,v 1.5 2003/11/17 21:20:27 ajzeneski Exp $ * * Copyright (c) 2001, 2002 The Open For Business Project - www.ofbiz.org * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included * in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT * OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR * THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ public class Main { public static String substring(String origin, int len) { if (origin == null || origin.equals("") || len < 1) return ""; byte[] strByte = new byte[len]; if (len > origin.getBytes().length) { return origin; } System.arraycopy(origin.getBytes(), 0, strByte, 0, len); int count = 0; for (int i = 0; i < len; i++) { int value = (int) strByte[i]; if (value < 0) { count++; } } if (count % 2 != 0) { len = (len == 1) ? ++len : --len; } return new String(strByte, 0, len); } }