breaking a file and storing it in a vector - in Java

Question

I am trying to store in an array the values of a file with the extension csv. This extension comes from a file made in excel, and when saved in this extension the values are separated through ";".

Through this image you can already imagine the final result you would like to arrive with the matrix.

Then, after reading the file, it follows my logic:

1 - Break row by row of this file I read.

2 - Store each row in a single vector using the split method, placing as parameter the delimiter (";").

3 - Pass from vector to matrix.

The problem is that when I store line by line in the vector, it stores only the last line I am inserting.

(Netbeans Print Console)

That is, instead of accumulating the entered values, it is overwriting the values each time the sequence goes to the bottom line.

Well, if I’m not getting past this part, it’s impossible to store the values inside the matrix. And please, I know that there are other solutions in Java to facilitate this process. But I’m really trying to work with simple logic and resources to get where I need to go.

So my difficulty is in storing each value in the vector using the split method().

Finally, follow the code I’ve already made!

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

public class EntradaSaidaIO {
    public static void main(String args[]) throws IOException{
        String matriz[][] = new String[26][26]; // Matriz onde contém 26 linhas e 26 colunas
        int n = 26*26; //
        String linhaF[] = new String[n]; //Vetor onde deveria armazenar os valores do arquivo

        InputStream e = new FileInputStream("C:\\Users\\Moraes\\Desktop\\MatrizApagar.csv");
        InputStreamReader er = new InputStreamReader(e);
        BufferedReader ebr = new BufferedReader(er);
        String texto = ebr.readLine(); // O método readLine()apens lê uma linha do arquivo

        while( texto != null){
            System.out.println(texto);
            linhaF = texto.split(";");
            /*
            for(int k = 0; k < linhaF.length; k++){
                System.out.print(linhaF[k]); // Apenas exibe o conteúdo dentro do vetor linhaF
            }
            */
            texto = ebr.readLine();
        }

        for(int i = 0; i < linhaF.length; i++){
            System.out.print(linhaF[i]); // Exibe todo o conteúdo armazenado
        }
        ebr.close();
    }
}

Answer 1

The problem is on line 20:

linhaF = texto.split(";");

A 26*26 vector has been created but it is being replaced with each iteration by the return of texto.split(";"), which is a size 26 vector, when your intention was to add it to the end. The vector does not have a native form (that I know of) to concatenate another vector, so you will have to do this manually:

 int j = 0;
 while(texto != null){
      System.out.println(texto);
      for(String str : texto.split(";")){
            linhaF[j++] = str;                  
      }             
      ...                
 }

Another way would be to work with some kind of Java List instead of the String vector:

ArrayList<String> linhaF = new ArrayList<String<();
...
while( texto != null) {
    linhaF.addAll(Arrays.asList(texto.split(";")));
    //Arrays
    ...
}