2D Array File Reader

Question

For my computer science class I'm making an website username/password program. I decided to use a 2D string array, and it hasn't been working out the best. I tried to make a file reader to read the logins that get written but I keep getting the ArrayIndexOutOfBoundsException error. My file reader code is below, and also included is my login input code. I am just starting Java so I have very basic programming knowledge.

private void fileReader() throws FileNotFoundException {

    File inFile = new File(filePath);


    try {

        Scanner freader = new Scanner(inFile);

        while (freader.hasNextLine()) {

            for (int j = 1; j <= pass.length; j++) {

                pass[j][0] = freader.nextLine();

                pass[j][1] = freader.nextLine();

                pass[j][2] = freader.nextLine();

            }
        }

        freader.close();

    } catch (IOException e) {

        System.err.println(e);
        System.exit(1);

    }

Login input:

private void input() throws InterruptedException, FileNotFoundException {



    for (int i = 0; i < pass.length; i ++){

            System.out.println(i);

            if (i == pass.length){
                add();
            }

            c.print("Please enter the website: ");

            pass[i][0] = c.readLine();

            c.print("Please enter your username: ");

            pass[i][1] = c.readLine();

            c.print("Please enter your password: ");

            pass[i][2] = c.readLine();

            while (true){

                c.clear();
                    synchronized (c) {
                        c.println("To continue adding logins, press C. To exit the program press ESC.");
                        c.println(pass[i][0] + " " +  pass[i][1] + " " +  pass[i][2]);
                    }
                if (c.isKeyDown(KeyEvent.VK_C)){
                    break;
                }
                else if (c.isKeyDown(KeyEvent.VK_ESCAPE)){
                    fileWriter();
                    pass();
                }

                Thread.sleep(10);

            }

    }




}

Any help is greatly appreciated!! Thanks!

Where is the ArrayIndexOutOfBoundsException ? In what line ? What is pass? How big is it ? What type is it ? — UDKOX
– UDKOX, Commented May 17, 2016 at 23:58
@UDKOX it starts off being 1 line, but increases by 1 each time the user adds a new login. — cfgfr0st
– cfgfr0st, Commented May 18, 2016 at 0:00
@T.Claverie I initialize it in the declaration, private String pass[][] = new String[1][3]; — cfgfr0st
– cfgfr0st, Commented May 18, 2016 at 0:00
for (int j = 1; j <= pass.length; j++) I think this is wrong, try for (int j = 0; j <= pass.length; j++). 0 instead of 1. — UDKOX
– UDKOX, Commented May 18, 2016 at 0:02

Fox · Accepted Answer · 2016-05-18 00:01:21Z

1

The main reason is because of this:

for (int j = 1; j <= pass.length; j++) { pass[j][0] = freader.nextLine(); pass[j][1] = freader.nextLine(); pass[j][2] = freader.nextLine(); }

An array starts from 0. By making j = 1, you are starting on the second array in the group, you need to start with 0 and read up to but not including the array length.

answered May 18, 2016 at 0:01

Fox

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1 Comment

cfgfr0st Over a year ago

Oops, I forgot I had it at 1. I was trying all sorts of things to try and fix it. I changed it to

for (int j = 0; j < pass.length; j++) {  					pass[j][0] = freader.nextLine();  					System.out.println(pass[j][0]);  					pass[j][1] = freader.nextLine();  					System.out.println(pass[j][1]);  					pass[j][2] = freader.nextLine();  					System.out.println(pass[j][2]);  				}

(dont mine the print, that was just to make sure it was printing the right values)

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