如何在 JSF 表中显示行号？答案

【问题标题】：How to display row numbers in JSF table?如何在 JSF 表中显示行号？
【发布时间】：2012-04-14 11:39:23
【问题描述】：

我有这个 JSF 表。我想添加行号。

<?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:h="http://java.sun.com/jsf/html"
      xmlns:f="http://java.sun.com/jsf/core"
      xmlns:ui="http://java.sun.com/jsf/facelets"
      >
    <h:head>
        <h:outputStylesheet library="css" name="table-style.css"  />
    </h:head>
    <h:body>

        <h1>JSF 2 dataTable example</h1>
        <h:form>
            <h:dataTable value="#{order.orderList}" var="o"
                styleClass="order-table"
                headerClass="order-table-header"
                rowClasses="order-table-odd-row,order-table-even-row"
            >
                        <h:column>

                    <f:facet name="header">No</f:facet>

                    <h:inputText value="#{order.orderList.rowIndex + 1}" size="10" rendered="false" />

                    <h:outputText value="#{order.orderList.rowIndex + 1}" rendered="#{not order.orderList.rowIndex + 1}" />

                </h:column>
                <h:column>

                    <f:facet name="header">Order No</f:facet>

                    <h:inputText value="#{o.orderNo}" size="10" rendered="#{o.editable}" />

                    <h:outputText value="#{o.orderNo}" rendered="#{not o.editable}" />

                </h:column>

                <h:column>

                    <f:facet name="header">Product Name</f:facet>

                    <h:inputText value="#{o.productName}" size="20" rendered="#{o.editable}" />

                    <h:outputText value="#{o.productName}" rendered="#{not o.editable}" />

                </h:column>

                <h:column>

                    <f:facet name="header">Price</f:facet>

                    <h:inputText value="#{o.price}" size="10" rendered="#{o.editable}" />

                    <h:outputText value="#{o.price}" rendered="#{not o.editable}" />

                </h:column>

                <h:column>

                    <f:facet name="header">Quantity</f:facet>

                    <h:inputText value="#{o.qty}" size="5" rendered="#{o.editable}" />

                    <h:outputText value="#{o.qty}" rendered="#{not o.editable}" />

                </h:column>

                <h:column>

                    <f:facet name="header">Action</f:facet>

                    <h:commandLink value="Edit" action="#{order.editAction(o)}" rendered="#{not o.editable}" />

                </h:column>

            </h:dataTable>

            <h:commandButton value="Save Changes" action="#{order.saveAction}" />

        </h:form>
    </h:body>

</html>


package com.mkyong;

import java.io.Serializable;
import java.math.BigDecimal;
import java.util.ArrayList;
import java.util.Arrays;

import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;

@ManagedBean(name="order")
@SessionScoped
public class OrderBean implements Serializable{

    private static final long serialVersionUID = 1L;

    private static final ArrayList<Order> orderList = 
        new ArrayList<Order>(Arrays.asList(

        new Order("A0001", "Intel CPU", 
                new BigDecimal("700.00"), 1),
        new Order("A0002", "Harddisk 10TB", 
                new BigDecimal("500.00"), 2),
        new Order("A0003", "Dell Laptop", 
                new BigDecimal("11600.00"), 8),
        new Order("A0004", "Samsung LCD", 
                new BigDecimal("5200.00"), 3),
        new Order("A0005", "A4Tech Mouse", 
                new BigDecimal("100.00"), 10)
    ));

    public ArrayList<Order> getOrderList() {

        return orderList;

    }

    public String saveAction() {

        //get all existing value but set "editable" to false 
        for (Order order : orderList){
            order.setEditable(false);
        }

        //return to current page
        return null;

    }

    public String editAction(Order order) {

        order.setEditable(true);
        return null;
    }

    public static class Order{

        String orderNo;
        String productName;
        BigDecimal price;
        int qty;
        boolean editable;

        public Order(String orderNo, String productName, BigDecimal price, int qty) {
            this.orderNo = orderNo;
            this.productName = productName;
            this.price = price;
            this.qty = qty;
        }

        public boolean isEditable() {
            return editable;
        }
        public void setEditable(boolean editable) {
            this.editable = editable;
        }
        public String getOrderNo() {
            return orderNo;
        }
        public void setOrderNo(String orderNo) {
            this.orderNo = orderNo;
        }
        public String getProductName() {
            return productName;
        }
        public void setProductName(String productName) {
            this.productName = productName;
        }
        public BigDecimal getPrice() {
            return price;
        }
        public void setPrice(BigDecimal price) {
            this.price = price;
        }
        public int getQty() {
            return qty;
        }
        public void setQty(int qty) {
            this.qty = qty;
        }
    }
}

我添加了#{order.orderList.rowIndex + 1} 以计算行数并显示数字。但是当我运行 JSF 页面时，我得到了这个错误：

java.lang.NumberFormatException: For input string: "rowIndex"
    at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
    at java.lang.Integer.parseInt(Integer.java:481)
    at java.lang.Integer.parseInt(Integer.java:514)
    at javax.el.ListELResolver.toInteger(ListELResolver.java:409)
    at javax.el.ListELResolver.getValue(ListELResolver.java:202)
    at com.sun.faces.el.DemuxCompositeELResolver._getValue(DemuxCompositeELResolver.java:176)
    at com.sun.faces.el.DemuxCompositeELResolver.getValue(DemuxCompositeELResolver.java:203)
    at com.sun.el.parser.AstValue.getValue(AstValue.java:138)
    at com.sun.el.parser.AstValue.getValue(AstValue.java:183)
    at com.sun.el.parser.AstNot.getValue(AstNot.java:63)
    at com.sun.el.parser.AstPlus.getValue(AstPlus.java:59)
    at com.sun.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:224)
    at com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:109)
    at javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:194)
    at javax.faces.component.UIComponentBase.isRendered(UIComponentBase.java:413)
    at javax.faces.component.UIData.iterate(UIData.java:1993)
    at javax.faces.component.UIData.processDecodes(UIData.java:1161)
    at javax.faces.component.UIForm.processDecodes(UIForm.java:225)
    at javax.faces.component.UIComponentBase.processDecodes(UIComponentBase.java:1176)
    at javax.faces.component.UIComponentBase.processDecodes(UIComponentBase.java:1176)
    at javax.faces.component.UIViewRoot.processDecodes(UIViewRoot.java:933)
    at com.sun.faces.lifecycle.ApplyRequestValuesPhase.execute(ApplyRequestValuesPhase.java:78)
    at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
    at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:593)
    at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1542)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:281)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
    at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:655)
    at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:595)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:161)
    at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:331)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:231)
    at com.sun.enterprise.v3.services.impl.ContainerMapper$AdapterCallable.call(ContainerMapper.java:317)
    at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:195)
    at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:849)
    at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:746)
    at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:1045)
    at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:228)
    at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:137)
    at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:104)
    at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:90)
    at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:79)
    at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:54)
    at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:59)
    at com.sun.grizzly.ContextTask.run(ContextTask.java:71)
    at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:532)
    at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:513)
    at java.lang.Thread.run(Thread.java:679)

我认为没有找到rowIndex。我该如何解决这个问题？

问候

【问题讨论】：

标签： java jsf jsf-2

【解决方案1】：

rowIndex 是 <h:dataTable> 组件本身的属性，而不是其 java.util.List 值的属性。

<h:dataTable binding="#{table}" ...>
    <h:column>#{table.rowIndex + 1}</h:column>
    ...
</h:dataTable>

您得到的异常基本上是告诉您正在尝试通过像orderList.get("rowIndex") 这样的字符串索引访问List 项目，这是无效的。访问列表项的唯一有效方法是使用像 #{order.orderList[0]} 这样解析为 orderList.get(0) 的大括号符号，但毕竟这不是您所需要的。

另一种方法是将orderList 包装在DataModel 属性中并将其作为值提供，例如

<h:dataTable value="#{order.orderModel}" ...>
    <h:column>#{order.orderModel.rowIndex + 1}</h:column>
    ...
</h:dataTable>

与

private transient DataModel orderModel;

public DataModel getOrderModel() {
    if (orderModel == null) {
        orderModel = new ListDataModel(orderList);
    }
    return orderModel;
}

应该只显示输出。在输入组件中显示它是没有意义的，因为不可能将总和设置为单值表达式。同样在rendered 属性中使用它的方式也是无效的，因为它不返回布尔值，而是一个长值。

【讨论】：

你知道更好的数据表示例吗？我拥有的不是很好，我发现了这个：balusc.blogspot.com/2006/06/using-datatables.html 这正是我需要的，但它适用于 JSF 1.2。有现代版吗？
阅读顶部的“通知”部分。
是的，我打开了 JSF 2.0 的示例，但是当我在这一行将代码导入 Netbeans 时出现错误： private Item item = new Item();有完整的例子源码吗？
只创建一个？另见文章正文。顺便说一句，这与您最初的问题无关。如果您有新问题，请提出新问题。

【解决方案2】：

另一种选择是使用List 的indexOf() 方法：

<h:outputText value="#{order.orderList.indexOf(o) + 1}"/>

【讨论】：

请注意，这需要 EL 2.2。此外，在大型列表和复杂对象的情况下，每次都在父列表中查找项目自己的索引会降低渲染性能。