Java File Rename renameFile(final File path, final String fname)

Description

Renames a file if the name alread exists.

License

Open Source License

Parameter

Parameter	Description
path	directory of the file
fname	file name

Exception

Parameter	Description
IOException	an exception

Return

a File object with the file name chenged

Declaration

public static File renameFile(final File path, final String fname) throws IOException 

Method Source Code

//package com.java2s;
/*=========================================================================
    /*from  ww w.  j av a  2 s  .  c  o  m*/
Copyright ? 2013 BIREME/PAHO/WHO
    
This file is part of TabNetCells.
    
TabNetCells 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.
    
TabNetCells 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 TabNetCells. If not, see
<http://www.gnu.org/licenses/>.
    
=========================================================================*/

import java.io.File;

import java.io.IOException;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class Main {
    /**
     * Renames a file if the name alread exists. Add an index to the name. 
     * xxxx.txt -> xxxx(1).txt
     * xxxx(1).txt -> xxxx(2).txt
     * @param path directory of the file
     * @param fname file name
     * @return a File object with the file name chenged
     * @throws IOException 
     */
    public static File renameFile(final File path, final String fname) throws IOException {
        if (path == null) {
            throw new NullPointerException("path");
        }
        if (fname == null) {
            throw new NullPointerException("fname");
        }

        final int dotIndex = fname.lastIndexOf('.');
        final String prefix = (dotIndex == -1) ? fname : fname.substring(0, dotIndex);
        final String suffix = (dotIndex == -1) ? "" : fname.substring(dotIndex);
        final Pattern pat = Pattern.compile(prefix + "\\((\\d+)\\)" + suffix);
        final Matcher mat = pat.matcher("");
        final String[] fNames = path.list();
        int last = 0;

        for (String name : fNames) {
            mat.reset(name);
            if (mat.matches()) {
                final int idx = Integer.parseInt(mat.group(1));
                if (last < idx) {
                    last = idx;
                }
            }
        }
        final String nName = prefix + "(" + (last + 1) + ")" + suffix;
        final File nfile = new File(path, nName);

        if (nfile.exists()) {
            throw new IOException("renameFile failed. File=[" + nName + "]");
        }
        return nfile;
    }
}

Related

1. renameFile(File src, File dest)
2. renameFile(File src, File dest, boolean overwrite)
3. renameFile(File srcFile, File destFile)
4. renameFile(File srcFile, File dstFile)
5. renameFile(File srcFile, File renameToFile)
6. renameFile(final String oldName, final String newName)
7. renameFile(String currentPath, String newPath)
8. renameFile(String file, String toFile)
9. renameFile(String fileFrom, String fileTo)