How to use h:selectBooleanCheckbox in a datatable to select multiple rows

Question

One way here is set a Boolean property like "isSelected" in the javaBean, and binding it with EL in jsp page which like this:
*<h:selectBooleanCheckbox value="#{var.isSelected}"/>*
but this break the a well EntityBean construction cause there is a null-meaning property in this bean just for getting data easily. So, if there is any other solutions for this? i use to think use EL like this:
*<h:selectBooleanCheckbox value="#{backBean.isSelected}">*
which bind the value to a Boolean type in the backBean ? but the problem here is there is only one boolean, how can it represent all those rows selected?
the second way is to get the whole view tree from FacesContext, and find all the checkbox component with findComponent() method,but i don't know how connect this to the rows in datatable,which means how to get a object from the checkbox componentID?
thanks,sorry for my english.

Answer 1

Here is a copy:
JSF<h:form>
    <h:dataTable value="#{myBean.dataList}" var="dataItem">
        <h:column>
            <f:facet name="header">
                <h:outputText value="Select" />
            </f:facet>
            <h:selectBooleanCheckbox value="#{myBean.selectedIds[dataItem.id]}" />
        </h:column>
    </h:dataTable>
    <h:commandButton value="Get selected items" action="#{myBean.getSelectedItems}" />
</h:form>MyBeanpackage mypackage;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
public class MyBean {
    // Init --------------------------------------------------------------------------------------
    private Map<Long, Boolean> selectedIds = new HashMap<Long, Boolean>();
    private List<MyData> selectedDataList;
    // Actions -----------------------------------------------------------------------------------
    public String getSelectedItems() {
        // Get selected items.
        selectedDataList = new ArrayList<MyData>();
        for (MyData dataItem : dataList) {
            if (selectedIds.get(dataItem.getId()).booleanValue()) {
                selectedDataList.add(dataItem);
                selectedIds.remove(dataItem.getId()); // Reset.
        // Do your thing with the MyData items in List selectedDataList.
        return "selected"; // Navigation case.
    // Getters -----------------------------------------------------------------------------------
    public Map<Long, Boolean> getSelectedIds() {
        return selectedIds;
    public List<MyData> getSelectedDataList() {
        return selectedDataList;
}Where each MyData item (dataItem) has an unique 'id' property.