java – Inserting data into an ArrayList

Question:

I have a problem to implement this code, I can't insert the data in the Arraylist.

public class Principal {
  public static void main(String[] args) {
        Faltas faltas = new Faltas();
        faltas.inserirDados(111,3,5);

        for(int j=0;j<faltas.size();j++){
                System.out.println(faltas.get(j).getDados());
        }
  }  
}

import java.util.ArrayList;
import java.util.List;
public class Faltas {
    int matricula;
    int mes;
    int dia;
    ArrayList<Faltas> faltas = new ArrayList();
    public Faltas(int matricula, int mes, int dia) {
        this.matricula = matricula;
        this.mes = mes;
        this.dia = dia;
    }
    public void inserirDados(int matricula,int mes, int dia) {
        faltas.addAll(matricula,mes,dia);
    }
    public String getDados(){
        return  "matricula: "+this.matricula+
                            "\nMes: "+this.mes+
                            "\nDia: "+this.dia+
                            "\n";
    }
}

Compilation error:

Exception in thread "main" java.lang.Error: Unresolved compilation problems: 
The constructor Faltas() is undefined
The method size() is undefined for the type Faltas
The method get(int) is undefined for the type Faltas

at TesteArray.Principal.main(Principal.java:9)

Answer:

I suggest taking a look at your object-oriented concepts. The fault has to be created as a simple object and the list is a union of several faults and is outside the base class. Below is the ideal form.

import java.util.ArrayList;

public class Principal {
  public static void main(String[] args) {
    ArrayList<Falta> faltas = new ArrayList();
    faltas.add(new Falta(111,3,5));

    for(int j=0;j<faltas.size();j++){
      System.out.println(faltas.get(j).getDados());
    }
  }  
}

public class Falta {
  int matricula;
  int mes;
  int dia;

  public Falta(int matricula, int mes, int dia) {
    this.matricula = matricula;
    this.mes = mes;
    this.dia = dia;
  }

  public String getDados(){
        return  "matricula: "+this.matricula+
                            "\nMes: "+this.mes+
                            "\nDia: "+this.dia+
                            "\n";
    }
}