Here you can find the source of getRelativePath(File src, File dst)
public static File getRelativePath(File src, File dst)
//package com.java2s; /************************************************************************* //from w w w .j a v a 2 s. c om Copyright (C) 2008 Grandite This file is part of Open ModelSphere. Open ModelSphere is free software; you can redistribute it and/or modify it under the terms of the GNU 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 General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA or see http://www.gnu.org/licenses/. You can reach Grandite at: 20-1220 Lebourgneuf Blvd. Quebec, QC Canada G2K 2G4 or open-modelsphere@grandite.com **********************************************************************/ import java.io.File; import java.util.ArrayList; public class Main { public static File getRelativePath(File src, File dst) { String sep = System.getProperty("file.separator"); String relativePath; String temp; int index; ArrayList directoryList1 = new ArrayList(); ArrayList directoryList2 = new ArrayList(); temp = src.toString(); while (temp.indexOf(sep) > -1) { directoryList1.add(temp.substring(0, temp.indexOf(sep))); temp = temp.substring(temp.indexOf(sep) + 1, temp.length()); } temp = dst.toString(); while (temp.indexOf(sep) > -1) { directoryList2.add(temp.substring(0, temp.indexOf(sep))); temp = temp.substring(temp.indexOf(sep) + 1, temp.length()); } relativePath = temp; index = 0; while ((index < directoryList1.size()) && (index < directoryList2.size()) && directoryList1.get(index).equals(directoryList2.get(index))) { index++; } int i; for (i = directoryList2.size() - 1; i >= index; i--) { relativePath = directoryList2.get(i).toString() + sep + relativePath; } int nbParentDir = directoryList1.size() - index; for (i = 0; i < nbParentDir; i++) { relativePath = ".." + sep + relativePath; } if (nbParentDir == 0) relativePath = "." + sep + relativePath; return new File(relativePath); } }