java file readline returns null

Question

I am trying to create a booking system in Java, however every time I run the program the while loop (shown below) skips straight to the end as though the line read was null

   //hardcoded file path - needs to be changed when program moved
            String fileName = "C:\\Users\\BOO\\Desktop\\SystemsSoftwareBookingsystem\\FilmData.txt";
            String line = null;
            int readInt = 0;
            float readFloat = 0;
            int item_counter = 0;

    try
            {

             BufferedReader bufferedReaderF = new BufferedReader(new FileReader(new File(fileName)));  

 while ((line = bufferedReaderF.readLine()) != null)
            {
                Film tmpFilm = new Film();

                switch (item_counter)
                {
                    case 0:
                {
                    line = bufferedReaderF.readLine();
                    tmpFilm.name = line;
                    item_counter++;
                    break;
                }
                case 1:
                {
                    readInt = bufferedReaderF.read();
                    tmpFilm.seatsTotal = readInt;
                    item_counter++;
                    break;
                }
                case 2:
                {
                    readInt = bufferedReaderF.read();
                    tmpFilm.seatsAvailable = readInt;
                    item_counter++;
                    break;
                }
                case 3:
                {
                    readInt = bufferedReaderF.read();
                    tmpFilm.price = readFloat;
                    item_counter++;
                    break;
                }
                case 4:
                {
                    readInt = bufferedReaderF.read();
                    tmpFilm.showingTime = readFloat;
                    item_counter++;
                    break;
                }
                case 5:
                {
                    readInt = bufferedReaderF.read();
                    tmpFilm.day = readInt;
                    item_counter++;
                    break;
                }
                case 6:
                {
                    readInt = bufferedReaderF.read();
                    tmpFilm.month = readInt;
                    item_counter++;
                    break;
                }
                case 7:
                {
                    readInt = bufferedReaderF.read();
                    tmpFilm.year = readInt;
                    item_counter = 0;
                    break;
                }
                }

                line = bufferedReaderF.readLine();

                server.filmList.add(tmpFilm);

            }

            bufferedReaderF.close();

        } catch (FileNotFoundException ex)
        {
            System.out.println("Unable to open file '" + fileName + "'");
        } catch (IOException ex)
        {
            System.out.println("Error reading file '" + fileName + "'");
        }
    }
}`

any ideas / help would be greatly appreciated

EDIT added rest of the code in the while loop as requested

EDIT here is the file I am reading from

Film 1
10
10
5.00
10.30
Wednesday 23rd
July
2013

Are you sure the file isn't empty?

Josh M
– Josh M

2013-08-19 16:10:17 +00:00
Commented Aug 19, 2013 at 16:10 — Josh M
– Josh M, Commented Aug 19, 2013 at 16:10

ajb · Accepted Answer · 2013-08-19 16:25:29Z

3

I don't know if this is related to the problem, but you need to put break; statements after every code sequence in your switch. Otherwise, if say item_counter is 0, it will execute the code for 0, and then fall through and execute the code for 1, and then for 2, etc.

answered Aug 19, 2013 at 16:25

ajb

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1 Comment

Joe Ikin Over a year ago

thanks for pointing that out - i've fixed that now but it wasn't what was causing the problem

Saj · Accepted Answer · 2013-08-19 16:30:31Z

0

Remove-

line = bufferedReaderF.readLine();

And read in the loop-

while ((line = bufferedReaderF.readLine()) != null)

Check if the file is empty. Can you also update your question with code inside while?

Based from your edit-

You are ignoring what you are reading in while. Should be something like this-

switch (item_counter)
{
    case 0:
    {
        tmpFilm.name = line;
        item_counter++;
        break;
    }
    case 1:
    {                    
        tmpFilm.seatsTotal = Integer.parseInt(line);
        item_counter++;
        break;
    }
    ...etc...

edited Aug 19, 2013 at 16:30

answered Aug 19, 2013 at 16:10

Saj

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5 Comments

Josh M Over a year ago

That bottom line does not compile, it needs to be while((line = bufferedReaderF.readLine()) != null){ ..... }.

Saj Over a year ago

@JimGarrison - His variable name is "bufferedReaderF".

Jim Garrison Over a year ago

I reverted the edit already; however, this answer does not appear to address the actual problem. The edit suggested, if not coupled with removing the additional read at the end of the loop will cause alternate input lines to be skipped.

Joe Ikin Over a year ago

i have tried making these changes but unfortunately it still won't work for some reason

Saj Over a year ago

@JimGarrison - The answer was given before the edit in question was made...also the edit in question was made because of what I requested in answer..

boxed__l · Accepted Answer · 2013-08-19 17:15:35Z

Try this...

BufferedReader bufferedReaderF = new BufferedReader(new FileReader(new File(fileName)));  
line = bufferedReaderF.readLine();
 while (line != null)
                {
                    Film tmpFilm = new Film();

                    switch (item_counter)
                    {
                        case 0:
                        {
                           // line = bufferedReaderF.readLine();
                            tmpFilm.name = line;
                            item_counter++;
                            break;
                        }
                        case 1:
                        {
                            readInt=Integer.parseInt(line);
                            tmpFilm.seatsTotal = readInt;
                            item_counter++;
                            break;
                        }
                        case 2:
                        {
                            readInt = Integer.parseInt(line);
                            tmpFilm.seatsAvailable = readInt;
                            item_counter++;
                            break;
                        }
                        case 3:
                        {
                            readFloat=Float.parseFloat(line);
                            tmpFilm.price = readFloat;
                            item_counter++;
                            break;
                        }
                        case 4:
                        {
                            readFloat=Float.parseFloat(line);
                            tmpFilm.showingTime = readFloat;
                            item_counter++;
                            break;
                        }
                        case 5:
                        {
                            line=line.replaceAll("\\D","");
                            readInt = Integer.parseInt(line);
                            tmpFilm.day = readInt;
                            item_counter++;
                            break;
                        }
                        case 6:
                        {
                            readInt = Integer.parseInt(GregorianCalendar.class.getField(line.toUpperCase()).get(line))+1;
                            tmpFilm.month = readInt;
                            item_counter++;
                            break;
                        }
                        case 7:
                        {
                            readInt = Integer.parseInt(line);
                            tmpFilm.year = readInt;
                            item_counter = 0;                   
                        }
                    }

                    line = bufferedReaderF.readLine();

                    server.filmList.add(tmpFilm);

                }

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