AND operator in regex

Question

I have the following date/time format:

25/01/2017às11:53:37

And the following regex:

REGX_DATAHORA_DISTRIBUICAO = "(?<data>\d{1,2}\/\d{1,2}\/\d{4})|(?<hora>\d{1,2}:\d{1,2}:\d{1,2})"

    private OffsetDateTime getDataDistribuicao() {
    String textoData = replaceAndTrim(this.getPaginaInfoGerais().<HtmlTableCell>getFirstByXPath(XPATH_CEL_DATA_DISTRIBUICAO)
            .getTextContent());
    return LocalDateTime
            .parse(getDataDistribuicao(textoData),
                    DateTimeFormatter.ofPattern(PATTERN_DATA_HORA))
            .atOffset(ZoneOffset.UTC);
}

private String getDataDistribuicao(final String dataTexto)  {
    final Matcher matcherDataHora = REGX_DATAHORA_DISTRIBUICAO.matcher(dataTexto);
    if (matcherDataHora.find()) {
        return matcherDataHora.group();
    } else {
        throw new RegexException("Data distribuição", REGX_DATAHORA_MOVIMENTACAO.pattern(), dataTexto);
    }
}

The regex has 2 groups, but only one group is returned, the one of the date.. The other group of time returns as null. I imagine it’s on the operator’s account...
I’ve tried using (?=(positive lookahead), but maybe I used it wrong.
What to do?

Answer 1

It has 2 groups, but the two groups return only part of the date: 25/01/2017.

In fact your groups return different things:

1. (?<data>\d{1,2}/\d{1,2}/\d{4}) - Returns: 25/01/2017

2. (?<hora>\d{1,2}:\d{1,2}:\d{1,2}) - Returns: 11:53:37

I took a test to prove it, you can see it here.

I imagine it’s on the operator’s account

I actually believe that you are not returning the entire result because you are using the method Matcher.group(), this method returns the matchs of a specific capture group, you can read the documentation on the use of it here.

What to do?

You can use:

private String getDataDistribuicao(final String dataTexto)  {
    final Matcher matcherDataHora = REGX_DATAHORA_DISTRIBUICAO.matcher(dataTexto);
    if (matcherDataHora.find()) {
        StringBuilder dataHora = new StringBuilder();
 dataHora.append(matcherDataHora.group("data")).append(matcherDataHora.group("hora"));
        return dataHora.toString;
    } else {
        throw new RegexException("Data distribuição", REGX_DATAHORA_MOVIMENTACAO.pattern(), dataTexto);
    }
}

If it doesn’t work, I suggest you try debugging the return values matcherDataHora.group("data") and matcherDataHora.group("hora"), if 1 of the two returns is empty, check if the input value you placed here is correct, because regex should capture this pattern.

Answer 2

Well, from what I researched, this problem is that the | (OR) operator in Java considers only one group. So what I did was go around it like I saw on some forums:

    private String getDataDistribuicao(final String dataTexto)  {
    String[] grupos = dataTexto.split("às");
    StringBuilder dataHora = new StringBuilder();
    for(String grupo: grupos){
        final Matcher matcherDataHora = REGX_DATAHORA_DISTRIBUICAO.matcher(grupo);
        if (matcherDataHora.find()) {
            dataHora.append(" ").append(grupo);
        } else {
            throw new RegexException("Data distribuição", REGX_DATAHORA_DISTRIBUICAO.pattern(), dataTexto);
        }
    }
    return dataHora.toString();
}