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Thread: What Wrong With My Code: IOException.

  1. #1
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    Post What Wrong With My Code: IOException.

        }	catch (IOException e){
        		System.err.println("File already exist: " + myFile);


    Its Still Overwrites The File?


  2. #2
    Forum Squatter newbie's Avatar
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    Default Re: What Wrong With My Code: IOException.

    Err what?
    Please elaborate.
    Please use [highlight=Java]//code goes here...[/highlight] tags when posting your code

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    Default Re: What Wrong With My Code: IOException.

    login = new JButton(" Login ");
    add(login);
    login.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent event) {

    File myFile = new File(username.getText() + ".txt");
    try {

    FileWriter fw = new FileWriter(myFile);
    PrintWriter pw = new PrintWriter(fw);
    pw.println("Username: " + username.getText());
    pw.println("Password: " + password.getText());

    pw.close();

    } catch (FileNotFoundException e) {
    System.err.println("File not found: " + myFile);
    } catch (IOException e){
    System.err.println("File already exist: " + myFile);
    } catch (Exception e) {
    e.printStackTrace();
    }



    Its a login system, and it keeps overwriting the files that's already there.

  4. #4
    Administrator copeg's Avatar
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    Default Re: What Wrong With My Code: IOException.

    Read the API for FileWriter...use the constructor that accepts an append boolean argument
    FileWriter (Java Platform SE 6)

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    Default Re: What Wrong With My Code: IOException.

    I've Read this twice but i dont understand how to add them, im not using filewriter as a class im using it as a try on a login button>?

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    Super Moderator Norm's Avatar
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    Default Re: What Wrong With My Code: IOException.

    not using filewriter as a class
    FileWriter fw = new FileWriter(myFile);
    From your code.
    That looks like you are using the FileWriter class.

    What does the following mean:
    im using it as a try on a login button

  7. #7
    Super Moderator Norm's Avatar
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    Default Re: What Wrong With My Code: IOException.

    Is this the same problem?
    FileWrite Over-Writing txt Files. D:

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    Default Re: What Wrong With My Code: IOException.

    Quote Originally Posted by Norm View Post
    Is this the same problem?
    FileWrite Over-Writing txt Files. D:
    no, i figared that out then i had a differnt problem lol

  9. #9
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    Default Re: What Wrong With My Code: IOException.

    Quote Originally Posted by Norm View Post
    FileWriter fw = new FileWriter(myFile);
    From your code.
    That looks like you are using the FileWriter class.

    What does the following mean:

    login = new JButton(" Login ");
    add(login);
    login.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent event) {
     
    File myFile = new File(username.getText() + ".txt");
    try {
     
    FileWriter fw = new FileWriter(myFile);
    PrintWriter pw = new PrintWriter(fw);
    pw.println("Username: " + username.getText());
    pw.println("Password: " + password.getText());
     
    pw.close();
     
    } catch (FileNotFoundException e) {
    System.err.println("File not found: " + myFile);
    } catch (IOException e){
    System.err.println("File already exist: " + myFile);
    } catch (Exception e) {
    e.printStackTrace();
    }

  10. #10
    Super Moderator Norm's Avatar
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    Default Re: What Wrong With My Code: IOException.

    How different?
    From this thread: Its Still Overwrites The File?
    title of the other thread: -filewrite-over-writing-txt-files-d.html

    What is the purpose of your post #9?

  11. #11
    Administrator copeg's Avatar
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    Default Re: What Wrong With My Code: IOException.

    Quote Originally Posted by Java Programmer View Post
    I've Read this twice but i dont understand how to add them, im not using filewriter as a class im using it as a try on a login button>?
    FileWriter fw = new FileWriter(myFile);

    How is this not using the FileWriter class? When you create a FileWriter, it creates a new file - overwriting any previous file UNLESS you have specified you wish to append, which you have not.

    Edit: as explained here. Please keep discussions in their appropriate threads and not duplicate discussions.
    Last edited by copeg; January 8th, 2012 at 06:14 PM.

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