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Thread: File exists or not

  1. #1
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    Default File exists or not

    Hi

    So, I have text on a textpane.

    When i hit the save button i want to know if the file already exists on the disk because in that case i want to "update" that file and if that file does not exists I want to create it with the text which is inside the textpane.

    When the the first hit on the save button will be this :
    if(fileChooser.showSaveDialog(this) != JFileChooser.APPROVE_OPTION)
                return;
     
            File f = fileChooser.getSelectedFile();
     
            if(f == null)
                return;
     
            try{
                FileOutputStream fout = new FileOutputStream(f);
                rtf.write(fout, textArea.getDocument(), 0, textArea.getDocument().getLength());
            }
            catch(IOException e) {}
            catch(BadLocationException e) {}
            catch(NullPointerException e) {}
            frame.setTitle(fileChooser.getSelectedFile().getName());
        }

    Ok, now I know that the file exists on the disc because with the code that i posted the final user saved it.

    The second hit in the same save button will just do the "update" of the file (modifications, etc).

    How can I do it ?

    Any tips please ?
    Last edited by helloworld922; December 26th, 2010 at 09:53 PM.


  2. #2
    Super Moderator helloworld922's Avatar
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    Default Re: File exists or not

    The easiest way for the computer to save a file is to simply over-write it (either that or append to it, though this could lead to rather large files).

    You can check if a file exists before-hand using file.exists().

    // creates the file specified by f is it doesn't exist
    if(!f.exists())
    {
        f.createNewFile();
    }

    However, I this is unnecessary because FileOutputStream automatically creates the file if it doesn't exist before-hand.

  3. #3
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    Default Re: File exists or not

    java write files

    use two way , you can see: http://java-er.com/tutorial/java-writing-files/

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