Adding characters to multiple filenames in Java

Question

I currently have a big folder full of filenames in the format:

EXA_0100_01012014.csv
EXA_0114_11012014.csv

Always the same 3 letters at the start. I need to change all of these filenames so that they are in the format:

EXA_B_0100_01012014

So it's just a case of inserting an _B (always _B) after the first three letters. I'm only just started learning Java so my attempts so far are fairly limited:

File oldfile = new File("EXA_0100_01012014.csv");
File newfile = new File("EXA_B_0100_01012014.csv");

I just need to do this for a large number of files all with the same 3 letter prefix. All the numbers change from file to file though.

If someone could give me a nudge in the right direction it would be much appreciated.

Thanks.

couldn't shell script be a better tool to solve this problem? :) — Amit Sharma, Jan 29 '14 at 15:44

score 2 · Answer 1 · answered Jan 29 '14 at 15:42

2

Use substring.

String fileName = "EXA_0100_01012014";
String newFileName = fileName.substring(0, 3) + "_B_" + fileName.substring(4);

Returns newFileName as:

EXA_B_0100_01012014

answered Jan 29 '14 at 15:42

Tom

15,798
4
37
48

score 1 · Answer 2 · answered Jan 29 '14 at 15:45

My suggestion:

String newFilename = oldfile.getFileName().replace("EXA_", "EXA_B_");
oldfile.renameTo(new File(newFilename));

If you don't like the replace() approach you could use the substring() method instead.

String oldFilename = oldfile.getFileName();
String newFilename = oldFilename.substring(0, 3) + "_B_" + oldFilename.substring(4);
oldfile.renameTo(new File(newFilename));

score 0 · Answer 3 · edited May 23 '17 at 11:49

0

Here is the results from a quick google bomb: First start looking at the renaming a file, Then you can instert a string by breaking the substrings apart and the prepending the first 3 characters and appending the rest after "_B". Similar to this.

edited May 23 '17 at 11:49

Community

1
1

answered Jan 29 '14 at 15:42

maximx1

89
5

score 0 · Answer 4 · answered Jan 29 '14 at 15:46

public static void main(String[] h) {

    final File folder = new File("/home/you/Desktop");
    renameFilesForFolder(folder);

}

public static void renameFilesForFolder(final File folder) {
    for (final File fileEntry : folder.listFiles()) {
        if (fileEntry.isDirectory()) {
            renameFilesForFolder(fileEntry);
        } else {
            if (fileEntry.getName().startsWith("EXA")) {
                fileEntry.renameTo(new File(fileEntry.getName().replaceAll("(EXA)(_)", "$1_B$2")));
            }
        }
    }
}

score 0 · Answer 5 · edited May 23 '17 at 12:03

Here is a possible solution.

I used the following links to help me:

Nagesh Chauhan's solution for file renaming http://www.beingjavaguys.com/2013/08/create-delete-rename-file-in-java.html

Philip Reichart's solution on file list How to get contents of a folder and put into an ArrayList

import java.io.File; import java.io.IOException;

public class RenameFiles {

public RenameFiles()
{
    File f = new File ("C:/work/play/java/list");
    File[] list = f.listFiles();

    for (int inum = 0; inum < list.length; inum++)
    {
        File curf = list[inum];
        RenameFile(curf);
    }
}

public void RenameFile(File curf) 
{
    String strfilename = curf.getAbsolutePath();
    StringBuffer buf = new StringBuffer(strfilename);
    int index = buf.indexOf("EXA_");
    buf.insert(index+4, "B_");

    String strnewfilename = buf.toString();
    strnewfilename = strnewfilename.replace('\\', '/');
    System.out.println(strnewfilename);

    File newFileName = new File(strnewfilename);

    try {  
        if (curf.renameTo(newFileName)) {  
            System.out.println("File "+strfilename+"renamed to "+strnewfilename+" successful !");  
        } else {  
            System.out.println("File "+strfilename+"renamed to "+strnewfilename+" failed !");  
        }  

    } catch (Exception e) {  
        e.printStackTrace();  
    }  
 }

public static void main(String[] args)
{
    RenameFiles fobj = new RenameFiles();               
}

}

Adding characters to multiple filenames in Java

5 Answers5