Java File Extension Name Get getFileExtension(File file)

Description

Returns the extension of a file or null if the file does not have one (no .

License

Open Source License

Parameter

Parameter	Description
file	a parameter

Return

The extension, trimmed and in lowercase.

Declaration

public static String getFileExtension(File file) 

Method Source Code

//package com.java2s;
/*  Copyright (C) 2003-2012 JabRef contributors.
This program 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 2 of the License, or
(at your option) any later version./*from   ww w .j  a v  a 2 s . c  om*/
    
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.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/

import java.io.*;

public class Main {
    /**
     * Returns the extension of a file or null if the file does not have one (no . in name).
     * 
     * @param file
     * 
     * @return The extension, trimmed and in lowercase.
     */
    public static String getFileExtension(File file) {
        String name = file.getName();
        int pos = name.lastIndexOf('.');
        String extension = ((pos >= 0) && (pos < name.length() - 1)) ? name.substring(pos + 1).trim().toLowerCase()
                : null;
        return extension;
    }
}

Related

1. getFileExtension(File file)
2. getFileExtension(File file)
3. getFileExtension(File file)
4. getFileExtension(File file)
5. getFileExtension(File file)
6. getFileExtension(File file)
7. getFileExtension(File file)
8. getFileExtension(File file)
9. getFileExtension(File file)