Generate Matrix Datatable with JSF Framework like Primefaces

Question

I want to create a 2D Datatable Matrix with Primefaces. I need to have fix columns and rows. So far I'm here:

But that's not what I exactly want. I want these kind:

My code looks like this one:

                <p:dataTable value="#{testBean.zeilen}" var="zeile" style="width:75%;" editable="true" editMode="cell">
                <p:column headerText="Exposition / Score"
                    styleClass="ui-widget-header" style="text-align:center;">
                    <h:outputText value="#{zeile}" />
                </p:column>

                <c:forEach items="#{testBean.werte}" var="w" >
                    <p:column headerText="#{w}">
                        <p:cellEditor>
                            <f:facet name="output">
                                <h:outputText value="#{w.entscheidung}" />
                            </f:facet>
                            <f:facet name="input">
                                <h:inputText value="#{w.entscheidung}" />
                            </f:facet>
                        </p:cellEditor>
                    </p:column>
                </c:forEach>

            </p:dataTable>

As you can see I got the data from my Bean, but in a wrong way. Each row with 16 elements but I want 4 in each row like in the second picture.