The page code is very simple and there is no complication. Check the “index.xhtml” code:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xmlns:ui="http://java.sun.com/jsf/facelets"
xmlns:h="http://java.sun.com/jsf/html" xmlns:f="http://java.sun.com/jsf/core" xmlns:p="http://primefaces.org/ui">
<h:head>
</h:head>
<h:body>
<f:view>
<h:form>
<p:dataTable id="lazyDataTable" value="#{playerMB.allPlayers}" var="player" paginator="true" rows="10"
selection="#{playerMB.player}" selectionMode="single"
paginatorTemplate="{CurrentPageReport} {FirstPageLink} {PreviousPageLink} {PageLinks} {NextPageLink} {LastPageLink} {RowsPerPageDropdown}"
rowsPerPageTemplate="5,10,15" style="width: 80%;margin-left: 10%;margin-right: 10%;">
<p:ajax event="rowSelect" update=":playerDialogForm" oncomplete="playerDetails.show()" />
<p:column>
<f:facet name="header">Name</f:facet>
<h:outputText value="#{player.name}" />
</p:column>
<p:column>
<f:facet name="header">Age</f:facet>
<h:outputText value="#{player.age}" />
</p:column>
</p:dataTable>
</h:form>
<p:dialog widgetVar="playerDetails" header="Player" modal="true">
<h:form id="playerDialogForm">
<h:panelGrid columns="2">
<h:outputText value="Id: " />
<h:outputText value="#{playerMB.player.id}" />
<h:outputText value="Name: " />
<h:outputText value="#{playerMB.player.name}" />
<h:outputText value="Age: " />
<h:outputText value="#{playerMB.player.age}" />
</h:panelGrid>
</h:form>
</p:dialog>
</f:view>
</h:body>
</html>
We got a lazy datatable that will display a selected value in a dialog.
In our Managed Bean we have a simpler code than the page:
package com.mb;
import java.io.Serializable;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.ViewScoped;
import org.primefaces.model.LazyDataModel;
import com.model.Player;
@ViewScoped
@ManagedBean
public class PlayerMB implements Serializable {
private static final long serialVersionUID = 1L;
private LazyDataModel<Player> players = null;
private Player player;
public LazyDataModel<Player> getAllPlayers() {
if (players == null) {
players = new PlayerLazyList();
}
return players;
}
public Player getPlayer() {
if(player == null){
player = new Player();
}
return player;
}
public void setPlayer(Player player) {
this.player = player;
}
}
We got a get/set to the Player entity and a get to the an object of the LazyDataModel type.
Check bellow the implementation of the PlayerLazyList code
package com.mb;
import java.util.List;
import java.util.Map;
import org.primefaces.model.LazyDataModel;
import org.primefaces.model.SortOrder;
import com.connection.MyTransaction;
import com.dao.PlayerDAO;
import com.model.Player;
public class PlayerLazyList extends LazyDataModel<Player> {
private static final long serialVersionUID = 1L;
private List<Player> players;
private MyTransaction transaction;
private PlayerDAO playerDAO;
@Override
public List<Player> load(int startingAt, int maxPerPage, String sortField, SortOrder sortOrder, Map<String, String> filters) {
try {
try {
transaction = MyTransaction.getNewTransaction();
playerDAO = new PlayerDAO(transaction);
transaction.begin();
// with datatable pagination limits
players = playerDAO.findPlayers(startingAt, maxPerPage);
// If there is no player created yet, we will create 100!!
if (players == null || players.isEmpty()) {
playerDAO.create100Players();
// we will do the research again to get the created players
players = playerDAO.findPlayers(startingAt, maxPerPage);
}
} finally {
transaction.commit();
}
} catch (Exception e) {
e.printStackTrace();
}
// set the total of players
if(getRowCount() <= 0){
setRowCount(playerDAO.countPlayersTotal());
}
// set the page dize
setPageSize(maxPerPage);
return players;
}
@Override
public Object getRowKey(Player player) {
return player.getId();
}
@Override
public Player getRowData(String playerId) {
Integer id = Integer.valueOf(playerId);
for (Player player : players) {
if(id.equals(player.getId())){
return player;
}
}
return null;
}
}
About the code above:
- The load method: the Primefaces will invoke this method every time that the pagination is fired. It will have all parameters with valid values; with these parameters you will be able to do a query in the database getting only for the needed data. If you want to sort your query by a field you can use the sortField attribute that will have the column datatable value (it will be null if the user do not order); the sortOrder will indicate if the user wants ascending or descending.
- The getRowKey method: this method return an id to each line, the Primefaces will invoke this method when needed.
- The getRowData method: will return a selected Player in the datatable.
- When you run this application the first time it will persist 100 players in the database. In a real application this would not be necessary.
A last configuration need to be added in the “web.xml” file:
<persistence-context-ref>
<persistence-context-ref-name>JSFPU</persistence-context-ref-name>
<persistence-unit-name>JSFPU</persistence-unit-name>
</persistence-context-ref>
We will use this configuration to do the JNDI Lookup.
Running our application
Now we just need to start up the application.
To access the application you can use the link:
http://localhost:8080/DatatableLazyPrimefaces/
Click here to download the source code of this post.
Reference: Lazy JSF Datatable Pagination (Primefaces) from our JCG partner Hebert Coelho at the uaiHebert blog.
bulllllcheeeeat
why JSPU??