content: /* ========================================================================
   * JCommon : a free general purpose class library for the Java(tm) platform
   * ========================================================================
   *
   * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
   * 
   * Project Info:  http://www.jfree.org/jcommon/index.html
   *
   * This library is free software; you can redistribute it and/or modify it 
   * under the terms of the GNU Lesser General Public License as published by 
   * the Free Software Foundation; either version 2.1 of the License, or 
   * (at your option) any later version.
   *
   * This library 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 Lesser General Public 
   * License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
   * USA.  
   *
   * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
   * in the United States and other countries.]
   * 
   * ------------
   * IOUtils.java
   * ------------
   * (C)opyright 2002-2004, by Thomas Morgner and Contributors.
   *
   * Original Author:  Thomas Morgner;
   * Contributor(s):   David Gilbert (for Object Refinery Limited);
   *
   * $Id: IOUtils.java,v 1.8 2009/01/22 08:34:58 taqua Exp $
   *
   * Changes
   * -------
   * 26-Jan-2003 : Initial version
   * 23-Feb-2003 : Documentation
   * 25-Feb-2003 : Fixed Checkstyle issues (DG);
   * 29-Apr-2003 : Moved to jcommon
   * 04-Jan-2004 : Fixed JDK 1.2.2 issues with createRelativeURL;
   *               added support for query strings within these urls (TM);
   */
  
  package org.jfree.io;
  
  import java.io.File;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.io.Reader;
  import java.io.Writer;
  import java.net.URL;
  import java.util.ArrayList;
  import java.util.Iterator;
  import java.util.List;
  import java.util.StringTokenizer;
  
  /**
   * The IOUtils provide some IO related helper methods.
   *
   * @author Thomas Morgner.
   */
  public class IOUtils {
  
      /** the singleton instance of the utility package. */
      private static IOUtils instance;
  
      /**
       * DefaultConstructor.
       */
      private IOUtils() {
      }
  
      /**
       * Gets the singleton instance of the utility package.
       *
       * @return the singleton instance.
       */
      public static IOUtils getInstance() {
          if (instance == null) {
              instance = new IOUtils();
          }
          return instance;
      }
  
      /**
       * Checks, whether the URL uses a file based protocol.
       *
       * @param url the url.
       * @return true, if the url is file based.
       */
      private boolean isFileStyleProtocol(final URL url) {
          if (url.getProtocol().equals("http")) {
              return true;
          }
          if (url.getProtocol().equals("https")) {
              return true;
          }
          if (url.getProtocol().equals("ftp")) {
              return true;
          }
          if (url.getProtocol().equals("file")) {
              return true;
          }
          if (url.getProtocol().equals("jar")) {
              return true;
          }
          return false;
      }
  
      /**
       * Parses the given name and returns the name elements as List of Strings.
       *
       * @param name the name, that should be parsed.
       * @return the parsed name.
       */
      private List parseName(final String name) {
          final ArrayList list = new ArrayList();
          final StringTokenizer strTok = new StringTokenizer(name, "/");
          while (strTok.hasMoreElements()) {
              final String s = (String) strTok.nextElement();
              if (s.length() != 0) {
                  list.add(s);
              }
          }
          return list;
      }
  
      /**
       * Transforms the name list back into a single string, separated with "/".
       *
       * @param name the name list.
       * @param query the (optional) query for the URL.
       * @return the constructed name.
       */
      private String formatName(final List name, final String query) {
          final StringBuffer b = new StringBuffer();
          final Iterator it = name.iterator();
          while (it.hasNext()) {
              b.append(it.next());
              if (it.hasNext()) {
                  b.append("/");
              }
          }
          if (query != null) {
              b.append('?');
              b.append(query);
          }
          return b.toString();
      }
  
      /**
       * Compares both name lists, and returns the last common index shared 
       * between the two lists.
       *
       * @param baseName the name created using the base url.
       * @param urlName  the target url name.
       * @return the number of shared elements.
       */
      private int startsWithUntil(final List baseName, final List urlName) {
          final int minIdx = Math.min(urlName.size(), baseName.size());
          for (int i = 0; i < minIdx; i++) {
              final String baseToken = (String) baseName.get(i);
              final String urlToken = (String) urlName.get(i);
              if (!baseToken.equals(urlToken)) {
                  return i;
              }
          }
          return minIdx;
      }
  
      /**
       * Checks, whether the URL points to the same service. A service is equal
       * if the protocol, host and port are equal.
       *
       * @param url a url
       * @param baseUrl an other url, that should be compared.
       * @return true, if the urls point to the same host and port and use the 
       *         same protocol, false otherwise.
       */
      private boolean isSameService(final URL url, final URL baseUrl) {
          if (!url.getProtocol().equals(baseUrl.getProtocol())) {
              return false;
          }
          if (!url.getHost().equals(baseUrl.getHost())) {
              return false;
          }
          if (url.getPort() != baseUrl.getPort()) {
              return false;
          }
          return true;
      }
  
      /**
       * Creates a relative url by stripping the common parts of the the url.
       *
       * @param url the to be stripped url
       * @param baseURL the base url, to which the <code>url</code> is relative 
       *                to.
       * @return the relative url, or the url unchanged, if there is no relation
       * beween both URLs.
       */
      public String createRelativeURL(final URL url, final URL baseURL) {
          if (url == null) {
              throw new NullPointerException("content url must not be null.");
          }
          if (baseURL == null) {
              throw new NullPointerException("baseURL must not be null.");
          }
          if (isFileStyleProtocol(url) && isSameService(url, baseURL)) {
  
              // If the URL contains a query, ignore that URL; do not
              // attemp to modify it...
              final List urlName = parseName(getPath(url));
              final List baseName = parseName(getPath(baseURL));
              final String query = getQuery(url);
  
              if (!isPath(baseURL)) {
                  baseName.remove(baseName.size() - 1);
              }
  
              // if both urls are identical, then return the plain file name... 
              if (url.equals(baseURL)) {
                  return (String) urlName.get(urlName.size() - 1);
              }
  
              int commonIndex = startsWithUntil(urlName, baseName);
              if (commonIndex == 0) {
                  return url.toExternalForm();
              }
  
              if (commonIndex == urlName.size()) {
                  // correct the base index if there is some weird mapping 
                  // detected,
                  // fi. the file url is fully included in the base url:
                  //
                  // base: /file/test/funnybase
                  // file: /file/test
                  //
                  // this could be a valid configuration whereever virtual 
                  // mappings are allowed.
                  commonIndex -= 1;
              }
  
              final ArrayList retval = new ArrayList();
              if (baseName.size() >= urlName.size()) {
                  final int levels = baseName.size() - commonIndex;
                  for (int i = 0; i < levels; i++) {
                      retval.add("..");
                  }
              }
  
              retval.addAll(urlName.subList(commonIndex, urlName.size()));
              return formatName(retval, query);
          }
          return url.toExternalForm();
      }
  
      /**
       * Returns <code>true</code> if the URL represents a path, and 
       * <code>false</code> otherwise.
       * 
       * @param baseURL  the URL.
       * 
       * @return A boolean.
       */
      private boolean isPath(final URL baseURL) {
          if (getPath(baseURL).endsWith("/")) {
              return true;
          }
          else if (baseURL.getProtocol().equals("file")) {
              final File f = new File(getPath(baseURL));
              try {
                  if (f.isDirectory()) {
                      return true;
                  }
              }
              catch (SecurityException se) {
                  // ignored ...
              }
          }
          return false;
      }
  
      /**
       * Implements the JDK 1.3 method URL.getPath(). The path is defined
       * as URL.getFile() minus the (optional) query.
       *
       * @param url the URL
       * @return the path
       */
      private String getQuery (final URL url) {
          final String file = url.getFile();
          final int queryIndex = file.indexOf('?');
          if (queryIndex == -1) {
              return null;
          }
          return file.substring(queryIndex + 1);
      }
  
      /**
       * Implements the JDK 1.3 method URL.getPath(). The path is defined
       * as URL.getFile() minus the (optional) query.
       *
       * @param url the URL
       * @return the path
       */
      private String getPath (final URL url) {
          final String file = url.getFile();
          final int queryIndex = file.indexOf('?');
          if (queryIndex == -1) {
              return file;
          }
          return file.substring(0, queryIndex);
      }
  
      /**
       * Copies the InputStream into the OutputStream, until the end of the stream
       * has been reached. This method uses a buffer of 4096 kbyte.
       *
       * @param in the inputstream from which to read.
       * @param out the outputstream where the data is written to.
       * @throws IOException if a IOError occurs.
       */
      public void copyStreams(final InputStream in, final OutputStream out)
          throws IOException {
          copyStreams(in, out, 4096);
      }
  
      /**
       * Copies the InputStream into the OutputStream, until the end of the stream
       * has been reached.
       *
       * @param in the inputstream from which to read.
       * @param out the outputstream where the data is written to.
       * @param buffersize the buffer size.
       * @throws IOException if a IOError occurs.
       */
      public void copyStreams(final InputStream in, final OutputStream out, 
              final int buffersize) throws IOException {
          // create a 4kbyte buffer to read the file
          final byte[] bytes = new byte[buffersize];
  
          // the input stream does not supply accurate available() data
          // the zip entry does not know the size of the data
          int bytesRead = in.read(bytes);
          while (bytesRead > -1) {
              out.write(bytes, 0, bytesRead);
              bytesRead = in.read(bytes);
          }
      }
  
      /**
       * Copies the contents of the Reader into the Writer, until the end of the 
       * stream has been reached. This method uses a buffer of 4096 kbyte.
       *
       * @param in the reader from which to read.
       * @param out the writer where the data is written to.
       * @throws IOException if a IOError occurs.
       */
      public void copyWriter(final Reader in, final Writer out)
          throws IOException {
          copyWriter(in, out, 4096);
      }
  
      /**
       * Copies the contents of the Reader into the Writer, until the end of the 
       * stream has been reached.
       *
       * @param in  the reader from which to read.
       * @param out  the writer where the data is written to.
       * @param buffersize  the buffer size.
       *
       * @throws IOException if a IOError occurs.
       */
      public void copyWriter(final Reader in, final Writer out, 
              final int buffersize)
          throws IOException {
          // create a 4kbyte buffer to read the file
          final char[] bytes = new char[buffersize];
  
          // the input stream does not supply accurate available() data
          // the zip entry does not know the size of the data
          int bytesRead = in.read(bytes);
          while (bytesRead > -1) {
              out.write(bytes, 0, bytesRead);
              bytesRead = in.read(bytes);
          }
      }
  
      /**
       * Extracts the file name from the URL.
       *
       * @param url the url.
       * @return the extracted filename.
       */
      public String getFileName(final URL url) {
          final String file = getPath(url);
          final int last = file.lastIndexOf("/");
          if (last < 0) {
              return file;
          }
          return file.substring(last + 1);
      }
  
      /**
       * Removes the file extension from the given file name.
       *
       * @param file the file name.
       * @return the file name without the file extension.
       */
      public String stripFileExtension(final String file) {
          final int idx = file.lastIndexOf(".");
          // handles unix hidden files and files without an extension.
          if (idx < 1) {
              return file;
          }
          return file.substring(0, idx);
      }
  
      /**
       * Returns the file extension of the given file name.
       * The returned value will contain the dot.
       *
       * @param file the file name.
       * @return the file extension.
       */
      public String getFileExtension(final String file) {
          final int idx = file.lastIndexOf(".");
          // handles unix hidden files and files without an extension.
          if (idx < 1) {
              return "";
          }
          return file.substring(idx);
      }
  
      /**
       * Checks, whether the child directory is a subdirectory of the base 
       * directory.
       *
       * @param base the base directory.
       * @param child the suspected child directory.
       * @return true, if the child is a subdirectory of the base directory.
       * @throws IOException if an IOError occured during the test.
       */
      public boolean isSubDirectory(File base, File child)
          throws IOException {
          base = base.getCanonicalFile();
          child = child.getCanonicalFile();
  
          File parentFile = child;
          while (parentFile != null) {
              if (base.equals(parentFile)) {
                  return true;
              }
              parentFile = parentFile.getParentFile();
          }
          return false;
      }
  }
  