Question

Iam使用EJB3.0 + JPA（hibernate）学习JSF

我从表中获取所有数据但在屏幕上却没有显示任何内容。这是代码。
托管Bean

package retail.web.mbean;

import java.sql.Timestamp;
import java.util.Calendar;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Properties;

import javax.faces.bean.ManagedBean;
import javax.faces.event.AjaxBehaviorEvent;
import javax.naming.InitialContext;
import javax.naming.NamingException;

import retail.ejb.service.OrderSessionBeanRemote;
import retail.model.vo.Customer;
import retail.model.vo.Order;
import retail.model.vo.Products;

@ManagedBean
public class OrdersMB {

    private Order order = new Order();

    private HashMap<Integer,String> customerMap = new HashMap<Integer,String>();

    private HashMap<Integer,String> productsMap = new HashMap<Integer,String>();

    private String customerName;

    private String productName;

    private List<Order> orderList;

    public Order getOrder() {
        return order;
    }

    public void setOrder(Order order) {
        this.order = order;
    }


    public HashMap<Integer, String> getCustomerMap() {
        return customerMap;
    }

    public void setCustomerMap(HashMap<Integer, String> customerMap) {
        this.customerMap = customerMap;
    }

    public HashMap<Integer,String> getProductsMap() {
        return productsMap;
    }

    public void setProductsMap(HashMap<Integer, String> productsMap) {
        this.productsMap = productsMap;
    }

    public String getCustomerName() {
        return customerName;
    }

    public void setCustomerName(String customerName) {
        this.customerName = customerName;
    }



    public String getProductName() {
        return productName;
    }

    public void setProductName(String productName) {
        this.productName = productName;
    }

    public List<Order> getOrderList() {
        return orderList;
    }

    public void setOrderList(List<Order> orderList) {
        this.orderList = orderList;
    }

    public void getOrderLists() throws NamingException{
        Properties p = new Properties();
        //p.put("java.naming.factory.initial","com.sun.jndi.cosnaming.CNCtxFactory");
        p.setProperty("java.naming.factory.initial", "com.sun.enterprise.naming.impl.SerialInitContextFactory");
        p.setProperty("java.naming.factory.url.pkgs", "com.sun.enterprise.naming");
        p.setProperty("java.naming.factory.state", "com.sun.corba.ee.impl.presentation.rmi.JNDIStateFactoryImpl");
        p.setProperty("org.omg.CORBA.ORBInitialHost", "localhost");
        p.setProperty("org.omg.CORBA.ORBInitialPort", "3700"); //any configured port different from 3700 - 34513
        InitialContext c = new InitialContext(p);
        OrderSessionBeanRemote remote = (OrderSessionBeanRemote) c.lookup("java:global/RetailProducts/OrderSessionBeanImpl!retail.ejb.service.OrderSessionBeanRemote");
         List<Order> orderList = remote.getOrderLists();
         setOrderList(orderList);


    }
public void deleteOrder(Order order) throws NamingException{
    Properties p = new Properties();
    //p.put("java.naming.factory.initial","com.sun.jndi.cosnaming.CNCtxFactory");
    p.setProperty("java.naming.factory.initial", "com.sun.enterprise.naming.impl.SerialInitContextFactory");
    p.setProperty("java.naming.factory.url.pkgs", "com.sun.enterprise.naming");
    p.setProperty("java.naming.factory.state", "com.sun.corba.ee.impl.presentation.rmi.JNDIStateFactoryImpl");
    p.setProperty("org.omg.CORBA.ORBInitialHost", "localhost");
    p.setProperty("org.omg.CORBA.ORBInitialPort", "3700"); //any configured port different from 3700 - 34513
    InitialContext c = new InitialContext(p);
    OrderSessionBeanRemote remote = (OrderSessionBeanRemote) c.lookup("java:global/RetailProducts/OrderSessionBeanImpl!retail.ejb.service.OrderSessionBeanRemote");
    remote.deleteOrder(order);
}

}

xhtml页面

<?xml version="1.0" encoding="ISO-8859-1" ?>
<!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:h="http://java.sun.com/jsf/html"
      xmlns:ui="http://java.sun.com/jsf/facelets"
      xmlns:c="http://java.sun.com/jsp/jstl/core"
      xmlns:f="http://java.sun.com/jsf/core">
<h:head>
<title>List of Orders</title>

    <script>
        window.onload = function() {
            document.getElementById('hidden:link').onclick();
        }
    </script>
        <h:outputStylesheet library="css" name="table-style.css"  />
    </h:head>
    <h:body>
   <h:form id="hidden" style="display:none">
        <h:commandLink id="link">
        <f:ajax event="click" listener="#{order.getOrderLists}"/>

        </h:commandLink>
    </h:form>
        <h1 style="background-color:#4863A0;color:white;">List of Orders</h1>
        <f:view>
 <h:form>
        <table class="order-table">
            <tr>
                <th class="order-table-header">Order #</th>
                <th class="order-table-header">Customer</th>
                <th class="order-table-header">Item</th>
                <th class="order-table-header">Action</th>
            </tr>
            <tbody>
                <ui:repeat var="o" value="#{order.orderList}" >

                  <tr>
                        <td class="order-table-even-row">#{o.orderID}</td>
                        <td class="order-table-even-row">#{o.customerName}</td>
                        <td class="order-table-even-row">#{o.productTile}</td>
                        <td class="order-table-even-row"><h:commandLink value="Delete" action="#{order.deleteOrder(o)}" /></td> 
                      </tr>

                </ui:repeat>
            </tbody>
        </table>
        </h:form>
        <table >

<tr><td>Total Customers: 1</td>
</tr>
</table>
<div style=" border-bottom: 5px ridge blue;"> </div> 

<table>
<tr>
<td><h:outputLink  value="createbook.xhtml">Create a new Order</h:outputLink>|</td><td><h:outputLink  value="eBusiness.jsp">Main Page</h:outputLink></td>
</tr>
</table>
</f:view>
    </h:body>
</html>

Answer 1

问题是您没有在任何地方加载列表内容。执行此操作的最佳位置是托管bean上的@PostConstruct。此外，由于您将在页面上调用ajax调用，因此将托管bean的范围设置为至少为@ViewScoped会更好：

@ManagedBean
@ViewScoped
public class OrdersMB {
    //attributes, methods, getters, setters...
    @PostConstruct
    public void init() {
        try {
            getOrderLists();
        } catch (NamingException ne) {
            //handle your error here...
        }
    }
}

如果您想使用ajax调用加载数据（因为它看起来您想要/需要），那么您忘记更新将显示数据的组件。您可以使用render的{{1}}属性来实现此目的。在这种情况下，您必须提供组件的完整ID，因为您正在更新表单之外的组件。

<f:ajax>

数据将显示在UI上

1 个答案: