如何在JTextArea中显示ArrayList

Question

I need to get display the elements of an ArrayList in a JTextArea including a new line after every single element. However, the code by now display all the elements in a single line, separated by commas; and openning and closing brackets "[ ]". The code by now is the following:

public void imprimirLista(ArrayList<Ausente> a) {
    for (Ausente s: a) {
        txtAreaAusentes.setText(a.toString());
    }
}

How can I print them without the commas and brakets?

Answer 1

You can also append the text:

public void imprimirLista(ArrayList<Ausente> a) {
    for (Ausente s : a) {
        txtAreaAusentes.append(s.toString() + "\n"); // New line at the end
    }
}

Answer 2

Try using txtAreaAusentes.append(s.toString()); One thing I'll note is this will append to any existing text that may be in that field. If you want to clear that text, then I would change the function to

public void imprimirLista(ArrayList<Ausente> a) {
    StringBuilder sb = new StringBuilder();
    for (Ausente s: a) {
        sb.append(s.toString());
    }
    txtAreaAusentes.setText(sb.toString());
}

Answer 3

You should replace a with s in your output:

String output = "";
for (Ausente s: a) {
   output += s.toString() + "\n";
}

txtAreaAusentes.setText(output);

Also build your output String first then set the text area to the output String . You can use a StringBuilder if you want to be more efficient...