Why is FileWriter not creating a new file ? FileNotFoundException

Question

So I have a code snippet as follows. Im trying to find out why it throws a FileNotFoundException.

File file= new File (WORKSPACE_PATH+fname);
FileWriter fw;
if (file.exists())
{
     fw = new FileWriter(file,true);//if file exists append to file. Works fine.
}
else
{
     fw = new FileWriter(file);// If file does not exist. Create it. This throws a FileNotFoundException. Why? 
}

Sorry for the noise guys. I had the wrong version. `git-pull` fixed it.Indeed the problem was with WORKSPACE_PATH — seeker, Aug 13 '14 at 17:04
this should be reopened, this is the first result on google, and the referenced https://stackoverflow.com/questions/10767117/why-filewriter-doesnt-create-a-new-file problem is permissions, not directory creation. I'd like to add an answer using the `Path` API. — xenoterracide, Dec 08 '20 at 18:32

score 7 · Answer 1 · answered Aug 13 '14 at 16:50

7

Using concatenation when creating the File won't add the necessary path separator.

File file = new File(WORKSPACE_PATH, fname);

answered Aug 13 '14 at 16:50

nbz

3,806
3
28
56

4

He does mention that opening for appending works fine though? – roelofs Aug 13 '14 at 16:53

score 4 · Answer 2 · 2018-01-17T14:29:56.557

4

You need to add a separator (Windows : \ and Unix : /, you can use File.separator to get the system's separator) if WORKSPACE_PATH does not have one at its end, and manually creating the file with its parent directories might help.

Try this if WORKSPACE_PATH does not have a separator at its end :

File file = new File(WORKSPACE_PATH + File.separator + fname);

And add this before fw = new FileWriter(file);

file.mkdirs(); // If the directory containing the file and/or its parent(s) does not exist
file.createNewFile();

edited Jan 17 '18 at 14:29

answered Aug 13 '14 at 17:00

And how you know that his `WORKSPACE_PATH` doesn't contain the separator? – Jonathan Drapeau Aug 13 '14 at 17:02
as he told append works fine that means no problem with the path of the file – SparkOn Aug 13 '14 at 17:03
Edited, I forgot to say that you don't need to add one if `WORKSPACE_PATH` already has one > – Aug 13 '14 at 17:04
Or you could use the two-arg form: `new File(WORKSPACE_PATH, fname)` – Kenster Aug 23 '14 at 22:12

score 2 · Answer 3 · answered Aug 13 '14 at 16:52

2

This might work:

File file= new File (WORKSPACE_PATH+fname);
FileWriter fw;
if (file.exists())
{
   fw = new FileWriter(file,true);//if file exists append to file. Works fine.
}
else
{
   file.createNewFile();
   fw = new FileWriter(file);
}

answered Aug 13 '14 at 16:52

roelofs

2,132
20
25

throws an `IOException` at that line. – seeker Aug 13 '14 at 16:54
What is the IOException message details? – roelofs Aug 13 '14 at 16:55
From what I can see, this should be fine - can you print the full `WORKSPACE_PATH+fname`, and confirm that it is trying to create it in the right place? – roelofs Aug 13 '14 at 16:59
[This](http://www.mkyong.com/java/how-to-append-content-to-file-in-java) does essentially what you're trying to do. – roelofs Aug 13 '14 at 17:00

Why is FileWriter not creating a new file ? FileNotFoundException

3 Answers3