Question

So im making a txt file reader, and the file has a bunch of “long” lines, because it is a prime number finder program, and it writes the numbers to the txt. when i stop the program, and then restart it, i want it to start where it left off. that means that i have to have it check each line and make sure that it is reading something, and the buffered reader is listed as long. here is the code:

try{
        FileReader fileReader = new FileReader(fileLocation);
        BufferedReader bufferedReader = new BufferedReader(fileReader);

        long stringRead = bufferedReader.read();

        while (stringRead != null)
        {
            stringRead = bufferedReader.read();
            currentNum =  stringRead;
        }

        bufferedReader.close();
        }
        catch(FileNotFoundException filenotfoundexxeption){
            System.out.print("file does not exist");
        }
        catch(IOException ioexception){
            ioexception.printStackTrace();
        }
}

so the problem is that it doesn’t like the stringRead != null, and i dont know how to do it otherwise. im a noob, and so please answer using the code already listed. Thanks!

Answer 1

You should probably be doing

String line;
while ((line = bufferedReader.readLine()) != null)
{
    currentNum = Long.parseLong(line);
}

As readLine() will return null when the end of file is reached.