static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
public static String leer(String message) {
String s;
try {
System.out.print(message);
s = br.readLine();
} catch (IOException ex) {
System.out.println("Hubo un error de lectura, vuelva a intentar");
s = null;
}
if (s == null) {
s = leer(message);
}
return s;
}
public static Double leerDouble(String message) {
Double d;
try {
d = Double.parseDouble(leer(message));
} catch (NumberFormatException ex) {
System.out.println("Valor incorrecto vuelva a intentar");
d = null;
}
if (d == null) {
d = leerDouble(message);
}
return d;
}