File Writer overrides previous write Java

Question

try {
                File file = new File(filePath+"usedcommands.txt");
                if (!file.exists()) {
                    file.createNewFile();
                }
                FileWriter fw = new FileWriter(file.getAbsoluteFile());
                BufferedWriter bw = new BufferedWriter(fw);
                bw.write(input+"\n");
                bw.close();
            } catch(Exception e) { System.out.println("can't write to usedcommands.txt..."); }

I'm writing to a txt file, but every time I run through the writing process it overrides what is already written there. How can I change my code so this part of the program doesn't override what is already there?

You can pass true in the FileWriter constructor to turn the append mode on. `FileWriter fw = new FileWriter("filename.txt", true);` — Amit, Feb 03 '14 at 20:28
duplicate of http://stackoverflow.com/questions/1225146/java-filewriter-with-append-mode — Krish Srinivasan, Feb 03 '14 at 20:29
BufferdWriter does not do this. FileWriter does this unless you tell it to append instead of overwriting. — Peter Lawrey, Feb 03 '14 at 20:35
@Arc Can you explain why it is not a duplicate because it looks like it to me? BTW You don't need to create a file just to append to it. It will create the file as required for you. — Peter Lawrey, Feb 03 '14 at 20:36
@PeterLawrey I have nothing to do with that question. I can understand though your concern though. — Arc, Feb 03 '14 at 20:39
@Arc I don't understand the question then because it answers it AFAIK. — Peter Lawrey, Feb 03 '14 at 20:41
@PeterLawrey I'm sorry I didn't check previous questions, my first instinct was to ask away. You are correct it does answer it. — Arc, Feb 03 '14 at 20:43
@Arc no issues. sometimes it is hard to tell. i know that myself. a second pair of eyes always helps. — Krish Srinivasan, Feb 03 '14 at 21:27

score 3 · Accepted Answer · answered Feb 03 '14 at 20:32

3

Pass true as a second argument to FileWriter to turn on "append" mode.

FileWriter fw = new FileWriter(file.getAbsoluteFile(), true);

answered Feb 03 '14 at 20:32

Lalit Chattar

1,914
8
27
49

+1 This should be the same as `FileWriter fw = new FileWriter(file, true);` as the FileWriter will just turn the `String` back into a `File`. – Peter Lawrey Feb 03 '14 at 20:56

score 1 · Answer 2 · edited Feb 03 '14 at 20:32

1

Use this it will work

fw = new FileWriter("fileName",true);

for more details on FileWriter see this

edited Feb 03 '14 at 20:32

Sotirios Delimanolis

274,122
60
696
724

answered Feb 03 '14 at 20:30

Girish

1,717
1
18
30

File Writer overrides previous write Java

2 Answers2

Linked

Related