Returns the file extension of the given file name. The returned value will contain the dot. : FilenameFilter « File Input Output « Java






Returns the file extension of the given file name. The returned value will contain the dot.

  
import java.net.URL;

/* 
 * 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);
 */


/**
 * The IOUtils provide some IO related helper methods.
 *
 * @author Thomas Morgner.
 */
public class Main {

  /**
   * 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);
  }
}

   
    
  








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