Arraylist of another class does not print elements

Question

I have a main class and another class, basically I have to read a CSV file in which the first line will have the materials of a student (matematica, portugues etc). The number of materials is N can be 8 or 800, so I recorded these materials in an arraylist. The teacher must compute grades to Kd student per subject, but he can also add subject or add and remove students, so I thought of working with another arraylist. The problem is that when saving the information in an arraylist to compute the notes I cannot print the arraylist, I see the msg ([Ljava.lang.String;@7e0babb1). Any idea what can be done to solve?

main class

import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Scanner;

import OpenFile.Marks;

public class OpenFile {

    public static void main(String[] args) {
        
    
        Scanner fileIn = new Scanner(System.in);
        
        ArrayList<String> firstRowSplit = new ArrayList<String>();
        String readerFirstLine;
        
        int n = 0 ; //using to count the lines in the file csv // for get the first row
        try {
                fileIn = new Scanner(new FileReader("marks.csv"));              // open the file marks.csv
                while ( n == 0 ) {                                  // read the file csv and get the first line
                    
                    readerFirstLine = fileIn.nextLine();                            // put the 1 line of file in a string                                                                                               
                    n++;
                    System.out.println(readerFirstLine);    
                
                    firstRowSplit = new ArrayList<String>(Arrays.asList(readerFirstLine.split(","))); //put the string(1º row) to into an arraylist
                    }
                                                                    
            
            }//try
            
            catch (FileNotFoundException e) {
                System.out.println("Error: " + e.getMessage());
            } // end catch
        

        
        for (int i = 0; i < firstRowSplit.size(); i++) {   //copy the arraylist elements for the object arraylist
            Marks.setMarkingCriteria(firstRowSplit);
            //System.out.println(firstRowSplit.get(i));
        }
                    
        Marks.add();
        Marks.show();
        
        
        
        Scanner in = new Scanner (System.in);   
        

        
        
    }//main

}//end 

and subclass

package OpenFile;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.Scanner;
import java.util.ArrayList;

public class Marks {
    private static ArrayList <String> markingCriteria = new ArrayList<String>();   
    private static ArrayList<String> students = new ArrayList<String>();
    private String id;
    
    

    public static ArrayList<String> add() {
        
        Scanner in = new Scanner(System.in);
        String[] getGradeArray =  new String[markingCriteria.size()];               //array to store marks
    
        for(int i = 0; i< markingCriteria.size(); i++) {
            System.out.println("tap the grade for: " + markingCriteria.get(i));
            String getGrade = in.nextLine();                                        //read the marks            
            getGradeArray[i] = getGrade;                                            //put the marks in an array
        }
        String stringOfMarks = getGradeArray.toString();
        students.add(stringOfMarks);
                
        return students;
    }
    
    public static ArrayList<String>  show() {
        
        for(int i = 0; i < students.size(); i++) {
            System.out.println(students.get(i));
                    
        }
        
        return students;
    }
    
    
    public  String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }
    
    
    public  ArrayList<String> getMarkingCriteria() {
        return markingCriteria;
    }
    public static  void setMarkingCriteria(ArrayList<String> markingCriteria) {
        Marks.markingCriteria = markingCriteria;
    }
    
    public  ArrayList<String> getStudents() {
        return students;
    }
    
    public  void setStudents(ArrayList<String> students) {
        this.students = students;
    } 
    

}

Answer 1

This happens because the method show is printing the contents of the variable students, that contains no element. I think what you would like to do is:

for(int i = 0; i < markingCriteria.size(); i++) {
    System.out.println(markingCriteria.get(i));
}

return markingCriteria;