Line Counter?

Question

Hi there,
I am trying to use Scanner to read a CSV file. I need to know how many lines there are in the file so I can create the right amount of elements for my array. We have not been taught how to use lists yet so that is what I am stuck with.
What is the best way to do this?
Thanks,

Answer 1

Hi Atholon,
I have some solutions for your problem.
Type 1: As you said read the file twice, first time get the count and second time read the data. Code is as below.
import java.io.*;
class FileTestReader
     public static void main(String[] args)
          System.out.println("File Reader");
          DataInputStream in = null;
          try
               // Open the file that is the first
               // command line parameter
               FileInputStream fstream = new FileInputStream("journal.txt");
               // Get the object of DataInputStream
               in = new DataInputStream(fstream);
               BufferedReader br = new BufferedReader(new InputStreamReader(in));
               String asd;
                    int count = 0;
                    //Read File Line By Line
                    while ((asd = br.readLine()) != null)  
                         count++;
                    System.out.println(count);
                    fstream = new FileInputStream("journal.txt");
                    // Get the object of DataInputStream
                    in = new DataInputStream(fstream);
                    br = new BufferedReader(new InputStreamReader(in));
                    //Read File Line By Line
                    while ((asd = br.readLine()) != null)  
                         //System.out.println(asd);
          }catch(Exception e)
               System.out.println(e);
          }finally
               try
                    //Close the input stream
                    in.close();
               catch(Exception e)
                    System.out.println(e);
}Type 2: Read once using Array List and transfer to String array. The code is as below.
import java.io.*;
import java.util.*;
class FileTestReader
     public static void main(String[] args)
          System.out.println("File Reader");
          DataInputStream in = null;
          try
               // Open the file that is the first
               // command line parameter
               FileInputStream fstream = new FileInputStream("journal.txt");
               // Get the object of DataInputStream
               in = new DataInputStream(fstream);
               BufferedReader br = new BufferedReader(new InputStreamReader(in));
               String asd;
                    int count = 0;
                    List ls = new ArrayList();
                    //Read File Line By Line
                    while ((asd = br.readLine()) != null)  
                         ls.add(asd);
                         count++;
                    System.out.println(count);
                    System.out.println(ls.size());
                    String outputStringArray[] = new String[ls.size()];
                    for(int i=0;i<ls.size();i++)
                         outputStringArray[i] = (String)ls.get(i);
                         System.out.println(ls.get(i));
          }catch(Exception e)
               System.out.println(e);
          }finally
               try
                    //Close the input stream
                    in.close();
               catch(Exception e)
                    System.out.println(e);
}Regards,
Zack