Deleting file contents android

Question

I need to delete the contents of a file, before I write more information into it. I've tried different ways, such as where I delete the content but the file stays the same size, and when I start writing in it after the deletion, a blank hole appears to be the size of the deletion before my new data is written.

This is what I've tried...

BufferedWriter bw;
try {
    bw = new BufferedWriter(new FileWriter(path));
    bw.write("");
    bw.close();
}
catch (IOException e) {
    e.printStackTrace();
}

And I've also tried this...

File f = new File(file);
FileWriter fw;

try {
    fw = new FileWriter(f,false);
    fw.write("");
}
catch (IOException e) {
    e.printStackTrace();
}

Can someone please help me with a solution to this problem.

Can't you just delete the file and create a new empty one? – Dalmas Jun 18 '12 at 09:57 — Dalmas, Jun 18 '12 at 09:57
No, I need to be the same file but thanks for your answer – kassy Jun 18 '12 at 10:20 — kassy, Jun 18 '12 at 10:20

score 8 · Answer 1 · answered Jun 18 '12 at 11:14

8

FileWriter (path, false)

The false will tell the writer to truncate the file instead of appending to it.

answered Jun 18 '12 at 11:14

mbwasi

3,612
3
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36

Yes, that's what I want because I want to clear the contents of the file. – kassy Jun 18 '12 at 13:14
Sorry, didnt see the false in the second piece of code there. – mbwasi Jun 18 '12 at 15:16

score 1 · Answer 2 · answered Jun 18 '12 at 10:01

1

Try calling flush() before calling close().

FileWriter writer = null;

try {
   writer = ... // initialize a writer
   writer.write("");
   writer.flush(); // flush the stream
} catch (IOException e) {
   // do something with exception
} finally {
   if (writer != null) {
      writer.close();
   }
}

answered Jun 18 '12 at 10:01

Genzer

2,921
2
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I tried but it still is the same. I do not understand. Thank you for your answer – kassy Jun 18 '12 at 10:21

score 1 · Answer 3 · answered Jun 18 '12 at 15:26

It might be because you are not closing the FileWriter, fw.close(); also you dont need to "delete" the old data, just start writing and it will overwrite the old data. So make sure you are closing everywhere.

This works for me:

    File f=new File(file);
    FileWriter fw;
    try {
        fw = new FileWriter(f);
        fw.write("");
       fw.close();
    } catch (IOException e) {
        e.printStackTrace();
    }

Deleting file contents android

3 Answers3