Tuesday, January 14, 2014

Primefaces DataTable Lazy Loading with pagination, filtering and sorting using JPA Criteria, @ViewScoped

Primefaces datatable lazy pagination works, but I was really frustrated after searching for a full example using Criteria in the web. So I've mixed solutions from

  • http://stackoverflow.com/questions/13972193/how-to-query-data-for-primefaces-datatable-with-lazy-loading-and-pagination
  • http://www.primefaces.org/showcase/ui/datatableLazy.jsf
  • http://www.javacodegeeks.com/2012/04/lazy-jsf-primefaces-datatable.html

To put all together in a complete example using

  • Primefaces 4.0
  • TomEE 1.6.0+ 
  • Criteria JPA
With


  • Filtering
  • Sorting
  • Pagination
  • Using @ViewScoped Managed Beans
So let's go

xhtml snippet

 <?xml version="1.0" encoding="UTF-8" ?>
<!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:f="http://java.sun.com/jsf/core"
    xmlns:h="http://java.sun.com/jsf/html"
    xmlns:ui="http://java.sun.com/jsf/facelets"
    xmlns:p="http://primefaces.org/ui">
<h:body>
    <h:form id="am">

            <p:dataTable
                var="element"
                value="#{inventoryManagerMB.model}"
                lazy="true"
                paginator="true"
                rows="10"
                paginatorTemplate="{RowsPerPageDropdown} {FirstPageLink} {PreviousPageLink} {CurrentPageReport} {NextPageLink} {LastPageLink}"
                rowsPerPageTemplate="10,50,100"
                id="sites">
 
            <p:column sortBy="id" filterBy="id" filterMatchMode="contains" headerText="ID">                
                <h:outputText value="#{element.id}" />
            </p:column>
            <p:column sortBy="name" filterBy="name" filterMatchMode="contains" headerText="Name">                
                <h:outputText value="#{element.name}" />
            </p:column>
            <p:column sortBy="siteType.name" filterBy="siteType.name" filterMatchMode="contains" headerText="Type">                
                <h:outputText value="#{element.siteType.name}" />
            </p:column>
            <p:column sortBy="ip" filterBy="ip" filterMatchMode="contains" headerText="IP">                
                <h:outputText value="#{element.ip} " />
            </p:column>
            <p:column sortBy="description" filterBy="description" filterMatchMode="contains" headerText="Description">                
                <h:outputText value="#{element.description}" />
            </p:column>
            </p:dataTable>
    </h:form>
</h:body>
</html>



 ManagedBean

@ManagedBean
@ViewScoped
public class InventoryManagerMB implements Serializable {

    private static final long serialVersionUID = -1201944101993687165L;

    @EJB
    private InventoryManagerEJB inventoryManagerEJB;
   
    private LazyDataModel<Site> model;
 



     @PostConstruct
    public void init() {
        try {
            this.model = new LazyDataModel<Site>(){
                private static final long    serialVersionUID    = 1L;
                @Override
                public List<Site> load(int first, int pageSize, String sortField, SortOrder sortOrder, Map<String, String> filters) {
                    List<Site> result = inventoryManagerEJB.getResultList(first, pageSize, sortField, sortOrder, filters);
                    model.setRowCount(inventoryManagerEJB.count(sortField, sortOrder, filters));
                    return result;
                }
            };
}


    public LazyDataModel<Site> getModel() {
        return model;
    }

    public void setModel(LazyDataModel<Site> model) {
        this.model = model;
    }
 

(...)

EJB

@Stateless
public class InventoryManagerEJB {
   
    @Inject
    private BaseService baseService;


    public List<Site> getResultList(int first, int pageSize, String sortField, SortOrder sortOrder, Map<String, String> filters) {
        List<Site> all = new ArrayList<Site>();
        all.addAll(this.baseService.getSiteDAO().getAll(first,pageSize,sortField,sortOrder,filters));
        return all;
    }

    public int count(String sortField, SortOrder sortOrder, Map<String, String> filters) {
        return this.baseService.getSiteDAO().getAll(-1,-1,null,null,filters).size();
    }
}


BaseService

@ApplicationScoped
public class BaseService implements Serializable{
   
    private static Logger log = Logger.getLogger(BaseService.class);
   
    /*
     * persistence
     */
   
    private static final long serialVersionUID = 588696475267901772L;

    @PersistenceContext

    private EntityManager entityManager;

    private SiteDAO siteDAO;


    @PostConstruct
    public void init() {
            siteDAO = new SiteDAO(entityManager);
    }



    public SiteDAO getSiteDAO() {
        return siteDAO;
    }


SiteDAO

public class SiteDAO extends GenericDAO<Site>{

    public SiteDAO(EntityManager entityManager) {
        super(entityManager);
    }


    public Collection<Site> getAll(int first, int pageSize, String sortField, SortOrder sortOrder, Map<String, String> filters) {
        CriteriaBuilder cb = entityManager.getCriteriaBuilder();
        CriteriaQuery<Site> q = cb.createQuery(Site.class);
        Root<Site> site = q.from(Site.class);
        Join<Site,SiteType> siteType = site.join(Site_.siteType);
        q.select(site);


        Path<?> path = getPath(sortField, site, siteType);
        if (sortOrder == null){
            //just don't sort
        }else if (sortOrder.equals(SortOrder.ASCENDING)){
            q.orderBy(cb.asc(path));
        }else if (sortOrder.equals(SortOrder.DESCENDING)){
            q.orderBy(cb.asc(path));
        }else if (sortOrder.equals(SortOrder.UNSORTED)){
            //just don't sort
        }else{
            //just don't sort
        }
       
        //filter
        Predicate filterCondition = cb.conjunction();
        for (Map.Entry<String, String> filter : filters.entrySet()) {
            if (!filter.getValue().equals("")) {
                //try as string using like
                Path<String> pathFilter = getStringPath(filter.getKey(), site, siteType);
                if (pathFilter != null){
                    filterCondition = cb.and(filterCondition, cb.like(pathFilter, "%"+filter.getValue()+"%"));
                }else{
                    //try as non-string using equal
                    Path<?> pathFilterNonString = getPath(filter.getKey(), site, siteType);
                    filterCondition = cb.and(filterCondition, cb.equal(pathFilterNonString, filter.getValue()));
                }
            }
        }
        q.where(filterCondition);
       
        //pagination
        TypedQuery<Site> tq = entityManager.createQuery(q);
        if (pageSize >= 0){
            tq.setMaxResults(pageSize);
        }
        if (first >= 0){
            tq.setFirstResult(first);
        }
        return tq.getResultList();
    }

    private Path<?> getPath(String field, Root<Site> site, Join<Site, SiteType> siteType) {
        //sort
        Path<?> path = null;
        if (field == null){
            path = site.get(Site_.name);
        }else{
            switch(field){
                case "id":
                    path = site.get(Site_.id);
                    break;
                case "name":
                    path = site.get(Site_.name);
                    break;
                case "siteType.name":
                    path = siteType.get(SiteType_.name);
                    break;
                case "ip":
                    path = site.get(Site_.ip);
                    break;
                case "description":
                    path = site.get(Site_.description);
                    break;
            }
        }
        return path;
    }

    private Path<String> getStringPath(String field, Root<Site> site, Join<Site, SiteType> siteType) {
        //sort
        Path<String> path = null;
        if (field == null){
            path = site.get(Site_.name);
        }else{
            switch(field){
                case "id":
                    path = null;
                    break;
                case "name":
                    path = site.get(Site_.name);
                    break;
                case "siteType.name":
                    path = siteType.get(SiteType_.name);
                    break;
                case "ip":
                    path = site.get(Site_.ip);
                    break;
                case "description":
                    path = site.get(Site_.description);
                    break;
            }
        }
        return path;
    }
}


Entity

@Entity
@Table(uniqueConstraints=@UniqueConstraint(columnNames={"name"}))
public class Site implements Serializable {
    /**
     *
     */
    private static final long serialVersionUID = 8008732613898597654L;
   
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;
   
    @Nameable
    @Column(nullable=false)
    private String name;
   
    private String ip;   
   
    private String description;
   
    @ManyToOne
    @JoinColumn(name="siteTypeId")
    private SiteType siteType;


(...)
}


That's it. Enjoy.

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