Being a novice in programming, I am currently attempting to save my objects as JSON in a text file. However, I have encountered difficulties when passing the JSON object to my constructor.
Here is the structure of my 'Aluno' class:
public class Aluno {
protected String matricula;
protected ArrayList<Integer> concluidas;
protected ArrayList<Integer> cursando;
protected ArrayList<Notas> notas;
This method is used to convert the class to JSON:
public JSONObject toJson(){
JSONObject json = new JSONObject();
json.put("matricula",this.matricula);
json.put("concluidas",this.concluidas);
json.put("notas",this.notas);
return json; }
The issue lies within the constructor:
public Aluno(JSONObject json) {
this.matricula = json.getString("matricula");
this.concluidas = (ArrayList<Integer>) json.get("concluidas");
this.notas = (ArrayList<Notas>) json.get("notas");
this.cursando = (ArrayList<Integer>) json.get("cursando");
}
An error is triggered at this line:
this.concluidas = (ArrayList<Integer>) json.get("concluidas");
ERROR : Exception in thread "main" java.lang.ClassCastException: json.JSONArray cannot be cast to java.util.ArrayList
A similar issue occurs with the 'cursando' and 'notas' ArrayLists.