Java - How do I read data into a list using bufferedReader and Scanner?

Question

I have a class called Runner which looks like this:

public class Runner 
{
   private static int nextNumber= 1;

   private int number;       
   private String name;      
   private String ageGroup;  
   private int time;         


   public Runner()
   {
      super();
      this.name = "";
      this.ageGroup = "standard";
      this.time = 0;
      this.number = nextNumber++;
    }

It also includes standard getter and setter methods. In another class I am trying to write a method that reads in data from a text file and assigns the data to a list. My method currently looks like this:

   public void readInRunners()
   {
      String pathname = OUFileChooser.getFilename();
      File aFile = new File(pathname);
      Scanner bufferedScanner = null;
      List<Runner> runners = new ArrayList<>();

      try
      {
         String name;
         int age;
         String ageGroup;
         Scanner lineScanner;
         String currentLine;
         bufferedScanner = new Scanner(new BufferedReader(new FileReader(aFile)));

         while (bufferedScanner.hasNextLine())
         {
            currentLine = bufferedScanner.nextLine();
            lineScanner = new Scanner(currentLine);
            lineScanner.useDelimiter(",");
            name = lineScanner.next();
            age = lineScanner.nextInt();

            if(age < 18)
            {
               ageGroup = ("junior");
            }

            else if(age >= 55)
            {
               ageGroup = ("senior");
            }

            else if(age >= 18 && age < 55)
            {
               ageGroup = ("standard");
            }

            runners.add(new Runner(name, ageGroup));
         }
      }

      catch (Exception anException)
      {
         System.out.println("Error: " + anException);
      }

      finally
      {
         try
         {
            bufferedScanner.close();
         }
         catch (Exception anException)
         {
            System.out.println("Error: " + anException);
         }
      }

I am getting an error on this line:

runners.add(new Runner(name, ageGroup));

I know that is isn't compiling because of the incompatible argument but I'm unsure how to phrase this otherwise.

Any advice would be greatly appreciated.

It honestly looks like your problem is not with reading from file. — M. Prokhorov, Mar 27 '17 at 13:22
Just a note, you don't need `this.time = 0;` , `time` will already be initialized to `0` (default value for an `int` variable). — Arnaud, Mar 27 '17 at 13:25

score 0 · Answer 1 · answered Mar 27 '17 at 13:22

0

I think that you should add a constructor

public Runner(String name, String age)
   {
     this.name = name,
     this.age= age;
   }

you have only empty constructor

public Runner(){// some code}

answered Mar 27 '17 at 13:22

Hamdy

430
1
6
19

score 0 · Answer 2 · answered Mar 27 '17 at 13:22

0

You need to have a parameterised constructor like in your runner class

public Runner(String name,String ageGroup)
   {
      this.name = name;
      this.ageGroup = ageGroup;
      this.time = 0;
      this.number = nextNumber++;
    }

answered Mar 27 '17 at 13:22

amudhan3093

740
9
17

Is there any reason why I might get the error: "variable ageGroup might not have been initialized" after doing this? – aTubOfAdam Mar 27 '17 at 16:14
Inside the try block you need to initialize like String ageGroup=""; since all the assignment statements are within if/else blocks – amudhan3093 Mar 27 '17 at 16:17
Try printing the age after you read from file.You will know the mistake – amudhan3093 Mar 27 '17 at 16:40
When I print out the ArrayList it's returning me the variable locations instead of the actual data. I've had this problem before but I don't remember the fix. – aTubOfAdam Mar 28 '17 at 12:29
You need to override toString() method in Runner class. http://stackoverflow.com/questions/29140402/how-do-i-print-my-java-object-without-getting-sometype2f92e0f4 – amudhan3093 Mar 28 '17 at 12:35
That's the one. Still getting issues, but don't think I want to labor the point any more in this thread. Thanks for the help. – aTubOfAdam Mar 28 '17 at 12:51

score 0 · Answer 3 · answered Mar 27 '17 at 13:22

0

Just add those arguments to the constructor in the runner class:

  public Runner(String name, String ageGroup)
   {
      super();
      this.name = name;
      this.ageGroup = ageGroup;
      this.time = 0;
      this.number = nextNumber++;
    }

answered Mar 27 '17 at 13:22

matiastofteby

431
4
18

Java - How do I read data into a list using bufferedReader and Scanner?

3 Answers3