read a data file and storing it in an array

[jwl]

I need to read a data file and store it in an array. It has to be an array because the first line has to indicate the number of data items to be read which is now 13.

It needs to be read from a method that looks like this:

private int[] readInputData(String fileName) {
       
   }

If someone can also explain how showing int[] in the first line of a method is useful that would be great.

[jwl]

Ok, I have this:

package readfile;
 
import java.io.File;
import java.io.IOException;
import java.util.Scanner;
 
public class ReadFile {
    private Scanner read;
 
   private void openFile() {
       try {
           read = new Scanner(new File("FIle.txt"));
       }
       catch (IOException e) {
           System.out.println("Could not open file input");
       }
   }
  
   private void readFile() {
       while(this.read.hasNext()) {
            String a = read.next();
            System.out.printf("%s\n", a);
       }
   }
   
   private void closeFile() {
       read.close();
   }
   
    public static void main(String[] args) {
        ReadFile file = new ReadFile();
        file.openFile();
        file.readFile();
        file.closeFile();
    }
}

It prints out 14 numbers starting with 13.
run:
13
105
112
105
111
112
113
107
118
108
110
109
112
108
BUILD SUCCESSFUL (total time: 1 second)

What I need to do is store all the numbers after 13 in an array of size 13 where the number 13 from the data file creates an array of size 13. Any help or direction will be great.

[jwl]

I think the method that does this should look something like this:

private int[] readFile(String File) {
       while(this.read.hasNext()) {
            String a = read.next();
            System.out.printf("%s\n", a);
            return new int[File];
       }
   }

Where "File" refers to the txt file but it says there is no return statement on line 1 of this code. On line 5 it has an error saying required int found String. I changed the readFile method a little but it's basically the same code as above. Am I going in the right direction here?

[Fubarable]

I wouldn't create a Scanner anywhere but inside of your readFile method since the File name String is passed in. What I would do, in pseudocode is something like:

method readFile accepts a fileName String parameter throws an IOException
  create new File, dataFile, with fileName
  create new Scanner object, fileScanner, with dataFile.
  use fileScanner to get first int, create an int array of this size
  use a for loop going from i = 0 to i < intArray.length to get ints with fileScanner and 
      place into int array. 
  close Scanner object.
  return int array.
end method