Thread: nextLine().split(",") not work correctly

Hi
there is a csv file that contain 10 rows and two columns.
i want to convert this csv file to array.
each cell contains several line of string.
but the output is wrong.
after printing output, each cell of array contains a line of one cell of csv file.


for example csv file contain

book, this book is good. that book is good.
cook, cooking is enjoyable.

after printing output of array:

book,this one is good
that book is good, null


what is wrong with this code?

code is :

   public static void main(String[] args) throws Exception {
 
          Scanner main = new Scanner(new File("C:\\Users\\a\\Desktop\\book1.csv"));
 
          int line=0;
          String [][] temp1=new String [10][2];
          while (main.hasNext()) {
          temp1[line]=main.nextLine().split(",");
          line++;
          }
}

You can use main as a name for any variable or method. You can also declare several main methods in your code.
There is absolutely no problem with that.

@saeedeh:
I do not see any critical errors in your code, maybe show us the code that generates the wrong output. It might be that your printing is not quite correct.

Well, that error makes a lot of sense.
Look at your code, you declare an array with a size of 10.

But you try to populate it with a while-loop that runs for as long as your scanner can read more input.
So there is a possibility that your scanner will read in more lines then 10, in this case an ArrayIndexOutOfBoundsException is inevitably.
Even if you are sure, that your file contains no more then 10 lines, its still a bad practice in general to not check for these kinds of errors.

What you could do is change the condition of your loop from:

main.hasNext()

to

main.hasNext() && line < temp1.length

this way you can be sure that you will never read more lines then your array can hold.

Furthermore, if you still wish to keep an exception in the case that your file has too many lines, you could add an if-then-else in which you throw your own, custom exception (or RuntimeException) that describes the problem in greater detail.

thanks again.
I correct that code and this error is corrected,
but main problem is still remain.
wrong data are stored in data.
the split character is "," but this character is ignored. and wrong data are stored in array.

Could you show us your code right now, both for populating the array and for printing the result?
It would also be useful if you could show us the output and the expected output.

Until then I can not help you.

i found the answer. i should write a file reader by using a opencsv.
because scanner takes each line in nextLine command.
and each cell contains several line that should be consider as one cell but in scanner each line of one cell goes to different cells.