Hi, I have to do registration (it will be composed of 4 consecutive numbers followed by 3 consecutive letters, without blank spaces between numbers and letters). And I want a method that receives a string enrollment and check that it has an appropriate format
I have done,
private final String matricula ="1111AAA";
Would that be fine? Or would you create a method?
You can use a regular expression:
^[0-9]{4}[A-Z]{3}$
Means that it only supports 4 digits ( [0-9]{4} ) followed by 3 letters ( [A-Z]{3} )
boolean comprobarMatricula (String matricula){
if (matricula.toUpperCase().matches("^[0-9]{4}[A-Z]{3}$")) {
System.out.println("Matrícula válida");
return true;
}else{
System.out.println("Matrícula inválida");
return false;
}
}
Here you would have a method to generate a valid license plate:
private static String generaMatricula()
{
//Letras válidas para matrícula
char[] array = {'B', 'C',
'D', 'F', 'G', 'H', 'J', 'K', 'L',
'M', 'N', 'P', 'R', 'S', 'T', 'V',
'W', 'X', 'Y', 'Z'};
String matricula = "";
for (int i=0; i<7; i++){
Random rnd = new Random();
int ale = (int)(rnd.nextDouble() * array.length); //Aleatorio para la letra
int ale2 = (int)(rnd.nextDouble() * 10); //Aleatorio entre 0-9
if (i>3) {
matricula += array[ale];
} else {
matricula += ale2;
}
}
return matricula;
}
Being able to call it in the following way:
System.out.println(generaMatricula());
Do you want to check if the registration is valid? For that we can create a method that checks through regular expressions if the registration is correct.
We must bear in mind that there is a European format and Old Spanish, for this we can use the following method that checks both cases or, if you are only interested in the European method, you can do a return false in the else of the first if
final String consonantes = "BCDFGHIJKLMNPQRSTUVWXYZ";
final Pattern patternES = Pattern.compile("(["+consonantes+"]{1,2})(\d{4})(["+consonantes+"]{0,2})");
final Pattern patternEU = Pattern.compile("(\d{4})(["+consonantes+"]{3})");
boolean checkMatricula(String matricula){
matricula = matricula.toUpperCase();
Matcher eu = patternEU.matcher(string);
if(eu.groupCount()>1){
return true;
}else {
Matcher es = patternES.matcher(string);
if(es.groupCount()>1){
return true;
}else {
return false;
}
}
}
Here you can also use the matcher to return the groups that are there, in the case of ES we have group 0 (all enrollment), 1 (first letters), 2 (numbers) and 3 (last letters) while the EU has the 0 (all enrollment), 1 (numbers) and 2 (letters)