Performance when generating a JSF table

Question

I’m having a question of how to improve perfomance when generating a table on a page using components JSF and Primefaces.

I am generating a table, after making an SQL query and mapping the object using Hibernate, more specifically, creating a list of objects using ResultTransformer interface.

I realize that this ok, doing TDD, when calling the data processing is fast.

But it has locked the page when it will generate it.

The page code goes like this:

<c:if test="#{bean.pojo.relatorioExtratoLojista != null}">
    <c:forEach var="loja" items="#{bean.buscarLojas()}">
        <c:forEach var="filial" items="#{bean.buscarFilial(loja)}">
            <c:forEach var="atendente" items="#{bean.buscarAtendente(filial)}">
                <c:forEach var="propostaStatus" items="#{bean.buscarPropostaStatus(atendente)}">
                    <p:panelGrid 
                        styleClass="panelGridCenter gridNoBackground" 
                        style="width: 100%; white-space:nowrap;">
                        <f:facet name="header">
                           // colunas do cabeçalho
                        </f:facet>
                        <c:forEach var="propostaCartao" items="#{bean.buscarPropostasCartao(atendente, propostaStatus)}" varStatus="propostaCartaoVarStatus">
                          // dados da tabela
                        </c:forEach>
                    </p:panelGrid>
                    <br/>
                </c:forEach>
            </c:forEach>
        </c:forEach>
    </c:forEach>

Where I put // colunas do cabeçalho the table header is generated, and the comment // dados da tabela has the table data.

The structure is this:

Map<Loja, Map<Filial, Map<Atendente, Map<PropostaStatus, List<PropostaCartao>>>>> mapLoja 

Some of the bean methods are:

public List<Loja> buscarLojas() {
    return new ArrayList<Loja>(this.getPojo().getRelatorioExtratoLojista().keySet());
}

public List<Filial> buscarFilial(Loja loja) {
    Map<Filial, Map<Atendente, Map<PropostaStatus, List<PropostaCartao>>>> mapFilial = this.getPojo().getRelatorioExtratoLojista().get(loja);
    return new ArrayList<Filial>(mapFilial.keySet());
}

public List<Atendente> buscarAtendente(Filial filial) {
    Map<Atendente, Map<PropostaStatus, List<PropostaCartao>>> mapAtendente = this.getPojo().getRelatorioExtratoLojista().
                                                                             get(filial.getLoja()).get(filial);
    return new ArrayList<Atendente>(mapAtendente.keySet());
}

public List<PropostaStatus> buscarPropostaStatus(Atendente atendente) {
    Map<Filial, Map<Atendente, Map<PropostaStatus, List<PropostaCartao>>>> mapFilial = this.getPojo().getRelatorioExtratoLojista().get(atendente.getLoja());
    Map<Atendente, Map<PropostaStatus, List<PropostaCartao>>> mapAtendente = mapFilial.get(atendente.getFilial());
    Map<PropostaStatus, List<PropostaCartao>> mapPropostaStatus = mapAtendente.get(atendente);
    if (NullUtil.isNull(mapPropostaStatus.keySet())) {
        toString();
    }
    return new ArrayList<PropostaStatus>(mapPropostaStatus.keySet());
}

public List<PropostaCartao> buscarPropostasCartao(Atendente atendente, PropostaStatus propostaStatus) {
    Map<Filial, Map<Atendente, Map<PropostaStatus, List<PropostaCartao>>>> mapFilial = this.getPojo().getRelatorioExtratoLojista().get(atendente.getLoja());
    Map<Atendente, Map<PropostaStatus, List<PropostaCartao>>> mapAtendente = mapFilial.get(atendente.getFilial());
    Map<PropostaStatus, List<PropostaCartao>> mapPropostaStatus = mapAtendente.get(atendente);
    return new ArrayList<PropostaCartao>(mapPropostaStatus.get(propostaStatus));
}

I when I put to debugar in the bean, I realized that the method buscarLojas() is called many times, apparently more than should.

I would like to know what I can do to improve the performance, since I have query to precisely decrease the amount of data.

Answer 1

To make official an answer.

The main problem in question is the lack of use of Lazyload and not in select. Page rendering, even with purely html element, are able to lock your browser considerably (you can test with tables above 500 lines), in the case of JSF, the result is even worse, since there is still a whole DOM management and an infinite sequence of requests for page construction.

Showing all the information in a table, which has no fixed amount of results, sooner or later proves to be a bad architectural choice, since they always tend to grow and generate low performance not only in the view, but a very large load on the server.

Adding a pagination to this list will certainly solve your problem.