Problem with the BufferedReader

I want to read a series of numbers from a txt file, so I did this to test if it gave me the first value:

try {
        Path p = Paths.get("DatosEA.txt");
        File f = p.toFile();
        FileReader fr = new FileReader(f);
        BufferedReader br = new BufferedReader(fr);

        String data;
        System.out.println("Revisión: " + br.readLine());
        System.out.println("Revisión (no de línea): " + br.read());

    br.close();

    } catch (FileNotFoundException ex) {
        ex.printStackTrace();
    } catch (IOException ex) {
        ex.printStackTrace();
    }

If this is in the DatosEA.txt:

116
118
123
135
141
147
154
165
166
166
168
174
179
186

But this output gives me:

Revisión: null
Revisión (no de línea): -1

What could have gone wrong? It should be noted that all this is within a class that extends JPanel called Grafico and I call it with a JPanel that is the object of that class in my window. I put the code inside an @Override paint method of the Graphic class.

Update: I have put the code inside the main of the main class of a new project and it works perfectly. I'm still looking for the source of the error.