Delete old files before adding new files in directory java without using FileUtils

Question

I am writing new files into a directory on daily basis.

BufferedWriter bw = new BufferedWriter(new FileWriter("C:\\difftest\\newfiles\\"+decisionList.get(i)+"_"+i+".txt"));

Before creating new files, I want to delete the previously added files existing in the folder. And the previous files will not override with new ones because the file names are different. How can I achieve this?

Do you want to delete all files within that directory or only those whose name follow a specific pattern? — Robert Kock, Nov 21 '18 at 09:40
If you want the directory empty, list the files in the directory and delete them all. Otherwise you'd also need some sort of filename matching. — Mark Jeronimus, Nov 21 '18 at 09:41
@RobertKock I want to delete all files,i.e, empty the entire directory before performing bufferedWriter. — Richa Sharma, Nov 21 '18 at 09:42
You can delete that directory, create again and save your new files. — Tran Ho, Nov 21 '18 at 09:42
@htpvl Can you tell how you are going to delete the directory (with files in it)? — prasad_, Nov 21 '18 at 10:08

score 0 · Answer 1 · edited Nov 21 '18 at 09:47

The following code can be helpful.

(This is just the idea of what you can do and I'm not sure about bugs.)

public class rename 
{ 
    public static void main(String[] argv) throws IOException 
    { 
         // Path of folder where files are located 
         String folder_path = 
           "C:\\Users\\Anannya Uberoi\\Desktop\\myfolder"; 

         // creating new folder 
         File myfolder = new File(folder_path); 

         File[] file_array = myfolder.listFiles(); 
         for (int i = 0; i < file_array.length; i++) 
         { 

            if (file_array[i].isFile()) 
            { 

                File myfile = new File(folder_path + 
                     "\\" + file_array[i].getName()); 
                myfile.delete(); 
            } 
        } 
    } 
}

thanks, @hamid this worked for me. – Richa Sharma Nov 22 '18 at 09:17 — Richa Sharma, Nov 22 '18 at 09:17

Pushpesh Kumar Rajwanshi · Accepted Answer · 2018-11-21T10:01:31.377

0

You can delete all existing files from the given directory using this one liner code,

Arrays.asList(new File("C:\\difftest\\newfiles").listFiles()).stream().forEach(File::delete);

So, just place this line of code before your BufferedWriter line, like this,

Arrays.asList(new File("C:\\difftest\\newfiles").listFiles()).stream().forEach(File::delete);
BufferedWriter bw = new BufferedWriter(new FileWriter("C:\\difftest\\newfiles\\"+decisionList.get(i)+"_"+i+".txt"));

edited Nov 21 '18 at 10:01

answered Nov 21 '18 at 09:54

Pushpesh Kumar Rajwanshi

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thanks @Pushpesh it worked:) – Richa Sharma Nov 22 '18 at 09:18
Glad to help Richa :) It showed me that you accepted my answer then suddenly I saw it got unaccepted. Any reasons? You didn't find my solution good enough? – Pushpesh Kumar Rajwanshi Nov 22 '18 at 09:20
1

accidently clicked accept icon twice. – Richa Sharma Nov 22 '18 at 09:34

Delete old files before adding new files in directory java without using FileUtils

2 Answers2