JSF2.0 分页代码的实现

JSF2中DataTable的实现并没有提供分页实现，相比于JSF1.2中可用的richfaces等实现中的分页来说，JSF2可用的其它实现包并不多。参考网上一位同学的代码，并修改它的代码的bug，形成了这个新的代码。
界面代码：

 <h:form>
        <h:dataTable  id="dt1" value="#{testPaginate.list}"  binding="#{testPaginate.htmlDataTable}"   border="1" var="item" rows="4" width="100%" headerClass="datagrid-header" >
	<h:column>
       			<f:facet name="choose">
       		 		<h:outputText value="chosse" />
        		</f:facet>
//这里实现了多选功能或者单选功能的实现
            <h:selectBooleanCheckbox >
                <f:ajax listener="#{testPaginate.ajaxSelect}" execute="@this"></f:ajax>
            </h:selectBooleanCheckbox>
            <h:commandButton action="#{testPaginate.select}"></h:commandButton>
                            <h:outputText value="#{item.name}"></h:outputText>
			</h:column>
            <h:column>
       			<f:facet name="header">
       		 		<h:outputText value="name" />
        		</f:facet>
                            <h:outputText value="#{item.name}"></h:outputText>
			</h:column>
			<h:column>
        		<f:facet name="header">
       	 			<h:outputText value="user"/>
        		</f:facet>
                            <h:outputText value="#{item.user}"></h:outputText>
			</h:column>
			</h:dataTable>
      
<h:outputText value="total:#{testPaginate.itemCount} "/>
<h:outputText value="per page:#{testPaginate.pageSize} "/>
<h:outputText value="total page:#{testPaginate.pageCount} "/>
<h:outputText value="current:#{testPaginate.pageIndex} "/>
//本来没有加ajax用来分页。后来发现这只对分页时第一页的selectonebooleancheckbox
//起作用。后来发现，如果不加render代码在commanbutton上面的话，使得提交后的界面的
//界面找不到majarra（firebug提示）。研究了半天（半碗水的水平，只能摸索着做了，呵
//呵），才解决
 <f:ajax execute="@form" render="@form">
 <h:commandButton  value="firstpage"  action="#{testPaginate.firstAction}" disabled="#{testPaginate.pageIndex == 1 || empty testPaginate.list}"/>
 <h:commandButton  value="prevpage"  action="#{testPaginate.prevAction}" disabled="#{testPaginate.pageIndex == 1 || empty testPaginate.list}"/>
 <h:commandButton  value="nextpage" action="#{testPaginate.nextAction}" disabled="#{testPaginate.pageIndex == testPaginate.pageCount || empty testPaginate.list}"/>
 <h:commandButton  value="lastpage"   action="#{testPaginate.lastAction}" disabled="#{testPaginate.pageIndex == testPaginate.pageCount || empty testPaginate.list}"/>
 <h:commandButton  value="load"   action="#{testPaginate.doSomething}"/>
 </f:ajax>
</h:form>

后台bean：

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

/**
 *
 * @author liujg
 */
@ManagedBean
@SessionScoped
public class TestPaginate {

    private HtmlDataTable htmlDataTable=new HtmlDataTable();

    public HtmlDataTable getHtmlDataTable() {
        return htmlDataTable;
    }

    public void setHtmlDataTable(HtmlDataTable htmlDataTable) {
        this.htmlDataTable = htmlDataTable;
    }

    public ArrayList<User> getList() {
        
           if(list.size()<1)
              for(int i=0;i<10;i++){
               User user=new User();
                user.setName("name"+i);
                user.setUser("user"+i);
                list.add(user);
              }
          
        return list;
    }



    public void setList(ArrayList<User> list) {
        this.list = list;
    }

    public ArrayList<User> selected=new ArrayList<User>();



    public ArrayList<User> getSelected() {
        return selected;
    }

    public void setSelected(ArrayList<User> selected) {
        this.selected = selected;
    }

    public void select(){
         int index=htmlDataTable.getRowIndex();
         User selectedUser=(User)htmlDataTable.getRowData();
         System.out.println("you choose "+index+" record ,and User is"+selectedUser.getName()+":::"+selectedUser.getUser());
    }
//ajaxSelect方法实现了多选功能。
    public void ajaxSelect(AjaxBehaviorEvent event){
           HtmlSelectBooleanCheckbox b = (HtmlSelectBooleanCheckbox)event.getComponent();
  HtmlSelectBooleanCheckbox def = (HtmlSelectBooleanCheckbox)event.getSource();
   System.out.println(b.isSelected());

               int index=htmlDataTable.getRowIndex();
         User selectedUser=(User)htmlDataTable.getRowData();
         System.out.println("you choose ajax"+index+" record ,and User is"+selectedUser.getName()+":::"+selectedUser.getUser());
         selected.add(selectedUser);
    }

    private ArrayList<User>  list=new  ArrayList<User>();

    public int getItemCount() {
        return htmlDataTable.getRowCount();
    }

    public int getPageCount() {
        double pageDouble = (htmlDataTable.getRowCount() + htmlDataTable.getRows() - 1) / htmlDataTable.getRows();
        int pageCount = (int) Math.ceil(pageDouble);
        return pageCount;
    }

    public int getPageSize() {
        return htmlDataTable.getRows();

    }

    public int getPageIndex() {
        if(htmlDataTable.getFirst()==0){
            return 1;
        }
        return htmlDataTable.getFirst()/htmlDataTable.getRows()+1;
    }

    public void doSomething(){
          htmlDataTable.setFirst(htmlDataTable.getFirst() + htmlDataTable.getRows());
    }

    public void nextAction() {
                htmlDataTable.setFirst(htmlDataTable.getFirst() + htmlDataTable.getRows());
    }

    public void lastAction() {
          htmlDataTable.setFirst(htmlDataTable.getRowCount()/htmlDataTable.getRows()*htmlDataTable.getRows());

    }

    public void firstAction() {

        htmlDataTable.setFirst(0);
    }

    public void prevAction() {

        htmlDataTable.setFirst(htmlDataTable.getFirst() - htmlDataTable.getRows());
    }


}

User类：