Java URL to File Name getFileExtensionByURL(URL url)

Description

Returns the file extension from the file part of the URL.

License

Open Source License

Parameter

Parameter	Description
url	the specified URL

Return

the file extension of the file part of the URL.

Declaration

public static String getFileExtensionByURL(URL url) 

Method Source Code

//package com.java2s;
/*/*from  www  .ja  v a 2 s. c om*/
 * Copyright (C) 2004 Sun Microsystems, Inc. All rights reserved. Use is
 * subject to license terms.
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the Lesser GNU General Public License as
 * published by the Free Software Foundation; either version 2 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.
 */

import java.net.URL;

public class Main {
    /**
     * Returns the file extension from the file part of the URL.
     * The returned file extension include the leading '.' character.
     * <P>
     * For example: if the URL is http://www.sun.com/index.html, the 
     * returned file extension is ".html".
     *
     * @param url the specified URL
     * @return the file extension of the file part of the URL.
     */
    public static String getFileExtensionByURL(URL url) {
        String trimFile = url.getFile().trim();

        if (trimFile == null || trimFile == "" || trimFile == "/") {
            return null;
        }

        int strIndex = trimFile.lastIndexOf("/");
        String filePart = trimFile.substring(strIndex + 1, trimFile.length());

        strIndex = filePart.lastIndexOf(".");
        if (strIndex == -1 || strIndex == filePart.length() - 1) {
            return null;
        } else {
            String fileExt = filePart.substring(strIndex, filePart.length());

            return fileExt;
        }
    }
}

Related

1. getFile(URL url)
2. getFile(URL url)
3. getFile(URL url, String description)
4. getFileAbsoluteURL(String[] directoryPaths, String fileName)
5. getFileDateTime(URL url)
6. getFileFor(URL url1)
7. getFileForURL(String url)
8. getFileForUrl(URL url)
9. getFileFrom(final URL url)