Primefaces Datatable-排序不起作用

Question

I have the problem in a JSF / xhtml page, that my primefaces datatable won't sort and filter correctly. I populate the datatable from my database, which works fine. However, as soon as I start to type something into the filter, or click on the header of a column to sort, all the entries disappear. I don't really know where my error here is. This is the code of the datatable in JSF:

<p:dataTable var="c" value="#{proposalController.contractList}">

    <p:column  headerText="ID" sortBy="#{c.id}" filterBy="#{c.id}" filterMatchMode="contains">
        <h:outputText value="#{c.id}" />
    </p:column>

    <p:column headerText="Customer Name" sortBy="#{c.custName}" filterBy="#{c.custName}" filterMatchMode="contains">
        <h:outputText value="#{c.custName}" />
    </p:column>

    <p:column headerText="Asset" sortBy="#{c.asset}" filterBy="#{c.asset}" filterMatchMode="contains">
        <h:outputText value="#{c.asset}" />
    </p:column>


</p:dataTable>

And this is the java code behind it:

package controller;
import java.util.Date;
import java.util.List;
import javax.annotation.PostConstruct;
import javax.ejb.EJB;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.ManagedProperty;
import javax.faces.bean.SessionScoped;
import model.Contract;
import model.ContractManager;

@ManagedBean (name="proposalController")
@SessionScoped
public class proposalController {

    @EJB
    private ContractManager contract;
    private int id;
    private String custName;
    private String custStreet;
    private String custZIP;
    private String custCity;
    private int creditScore;
    private String custPers;
    private String mail;
    private String phone;
    private Date start;
    private Date endd;
    private String asset;
    private String insurance;
    private double rate;
    private String status;
    private List<Contract> contractList;  




    public List<Contract> getContractList() {
        this.contractList = contract.getContractList();
        return this.contractList;
    }

It would be great if someone could help me!

Answer 1

In your getContractList() method, you return a list from some service, which is probably a new list everytime the method is called. You should instead get this list just once from your service on initialization (some @PostConstruct -annotated method for instance), save it in your session-bean and return the list from your session-bean instead.

Something like this:

@ManagedBean (name="proposalController")
@SessionScoped
public class proposalController {
    @EJB
    private ContractManager contract;

    private List<Contract> contractList;

    @PostConstruct
    public void init() {
        contractList = contract.getContractList();
    }

    public List<Contract> getContractList() {
        return this.contractList;
    }
}