CODEWITHSUNDEEP
javaiojava.util.scannerbufferedreader
user12192927
user12192927

Reputation: 23

Cannot read last line of file, loop is not entered

I am trying to read in a .txt file into java. Regardless if it ends on a blank line or not, the reader will not read in the last line, and the program won't terminate.

public static ArrayList<String> readInput() {
        // TODO Auto-generated method stub
        ArrayList<String> input = new ArrayList<>();
        Scanner scanner = new Scanner(System.in);


//      while (scanner.hasNextLine()) {
//          String line = scanner.nextLine();
//          if (line.equals("") || line.isEmpty()) {
//                break;
//            }  
//           input.add(line);
//           System.out.println(line);
//      }
        String line;
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        try {
            while((line = reader.readLine()) != null && !line.isEmpty()) {

                input.add(line);
                System.out.println(line);
            }
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            JOptionPane.showMessageDialog(null,"File not found or is unreadable.");
        }finally {
            try {
                reader.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        //PROGRAM WILL NOT GO BEYOND THIS POINT.
        JOptionPane.showMessageDialog(null,"File has finished reading.");
         return input;

Here, I tried two methods. One with a buffered reader, and the other with a scanner, but neither works. Here is a snippet of the .txt file:

...some more lines...
33
0 0 0
1 0 0
0 1 0
34
0 0 0
1 0 0
1 0 0
35
0 1 0
0 1 0
0 0 1
36
1 0 0
0 1 0
0 1 0

The program will read up to the second last line. So this'll be what i see:

...some lines...
0 0 1
36
1 0 0
0 1 0

and the program will still be running. It won't even re-enter the while loop (i tested it with a println).

Even if i was to add a blank line after the last line like so:

...some lines...
0 0 1
36
1 0 0
0 1 0
0 1 0
<a blank line>

The program will read up to the last line of numbers, be unable to re-enter the loop, and the program will not terminate.

...some lines...
0 0 1
36
1 0 0
0 1 0
0 1 0

I've tried looking everywhere for solutions but can't seem to find one that actually solves this issue.

Preferably, I would like to follow scenario 1 where I do not end the text file with a blank line.

also each line of the .txt file ends on a new line, and contains no trailing white spaces. Thanks!

Upvotes: 0

Views: 371

Answers (1)

nic
nic

Reputation: 139

You need an EOF character in order for your program to terminate. Try typing CTRL-D in your console, that will end the execution.

Upvotes: 0

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