Struts2(十)OGNL标签二与Struts2标签
一、Struts2标签的优势
标签库简化了用户对标签的使用
结合OGNL使用，对于集合、对象的访问功能非常强大
提供可扩展的主题、模板支持、极大简化了视图页面的编写
不依赖任何表现层技术
Struts2标签的分类：
通用标签（Generir Tags）
- 数据标签（Data Tags）
- 控制标签（Control Tags）
UI标签（UI Tags）
Ajax标签（Ajax Tags)
二、数据标签
web.xml
<filter> <filter-name>struts2</filter-name> <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class> </filter> <filter-mapping> <filter-name>struts2</filter-name> <url-pattern>/*</url-pattern> </filter-mapping>
三个实体类
package com.pb.entity; /* * 地区类 */ public class District { private int districtId; //地区编号 private String districtName; //地区名称 public District() { super(); // TODO Auto-generated constructor stub } public District(int districtId, String districtName) { super(); this.districtId = districtId; this.districtName = districtName; } public int getDistrictId() { return districtId; } public String getDistrictName() { return districtName; } public void setDistrictId(int districtId) { this.districtId = districtId; } public void setDistrictName(String districtName) { this.districtName = districtName; } } package com.pb.entity; /* * 街道 */ public class Street { private int streetId; //街道ID private String streetName; //街道名称 private District district; //街道所在地区 public Street() { super(); // TODO Auto-generated constructor stub } public Street(int streetId, String streetName, District district) { super(); this.streetId = streetId; this.streetName = streetName; this.district = district; } public District getDistrict() { return district; } public int getStreetId() { return streetId; } public String getStreetName() { return streetName; } public void setDistrict(District district) { this.district = district; } public void setStreetId(int streetId) { this.streetId = streetId; } public void setStreetName(String streetName) { this.streetName = streetName; } } package com.pb.entity; import java.util.Date; /* * 房屋 */ public class House { private int houseId; //房屋ID private String title; //房屋标题 private Street street;//房屋所在街道 private Date addDate;//房屋发布日期 private String desc; //房屋描述 public House() { super(); // TODO Auto-generated constructor stub } public House(int houseId, String title, String desc, Date addDate, Street street) { super(); this.houseId = houseId; this.title = title; this.desc = desc; this.addDate = addDate; this.street = street; } public Date getAddDate() { return addDate; } public String getDesc() { return desc; } public int getHouseId() { return houseId; } public Street getStreet() { return street; } public String getTitle() { return title; } public void setAddDate(Date addDate) { this.addDate = addDate; } public void setDesc(String desc) { this.desc = desc; } public void setHouseId(int houseId) { this.houseId = houseId; } public void setStreet(Street street) { this.street = street; } public void setTitle(String title) { this.title = title; } }
houseaction
package com.pb.web.action; import java.util.ArrayList; import java.util.Date; import java.util.List; import com.opensymphony.xwork2.ActionSupport; import com.pb.entity.District; import com.pb.entity.House; import com.pb.entity.Street; public class HouseAction extends ActionSupport { /** * */ private static final long serialVersionUID = 1L; private List<House> houses; @Override public String execute() throws Exception { //声明地区 District dt1=new District(75501,"宝安区"); District dt2=new District(75502,"南山区"); //声明街道 Street street1=new Street(74,"布心一村",dt1); Street street2=new Street(25,"商业街",dt1); Street street3=new Street(87,"科技园",dt2); Street street4=new Street(99,"南头古城",dt2); //房屋 House house1=new House(11,"一房一厅","靠近公园",new Date(),street1); House house2=new House(12,"二房一厅","环中线",new Date(),street2); House house3=new House(13,"单间","高新公寓",new Date(),street3); House house4=new House(14,"一房一厅","靠近中山公园",new Date(),street4); houses=new ArrayList<House>(); //添加 houses.add(house1); houses.add(house2); houses.add(house3); houses.add(house4); return SUCCESS; } public List<House> getHouses() { return houses; } public void setHouses(List<House> houses) { this.houses = houses; } }
struts.xml
<package name="default" namespace="/" extends="struts-default"> <action name="house" class="com.pb.web.action.HouseAction"> <result name="success"> /houseList.jsp </result> </action> </package>
页面
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@ taglib prefix="s" uri="/struts-tags"%> <% //绝对路径 String path = request.getContextPath(); String basePath = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort() + path + "/"; %> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <!-- 引入绝对路径 --> <base href="<%=basePath%>"> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>房屋列表信息</title> </head> <body> <!--房屋列表中第一个房屋的信息标题 --> 房屋列表中第一个房屋的信息标题 :<s:property value="houses[0].title"/><br/> 房屋列表中第一个房屋的信息ID :<s:property value="houses[0].houseId"/><br/> <!--房屋列表中第一个房屋的信息标题 --> 房屋列表中第一个房屋的信息标题 :<s:property value="" default="默认信息"/><br/> <!--是否转义HTML,将OGNL转化为字符要加单引号 --> 是否转义HTML:<s:property value="'<hr/>'" /><br/> <!--是否转义HTML 将OGNL转化为字符要加单引号 escapeXml默认为true --> 是否转义HTML:<s:property value="'<hr/>'" escapeHtml="false" /><br/> <!--s:date标签格式化日期 --> 房屋列表中第一个房屋的发布日期 未格式:<s:property value="houses[0].addDate"/><br/> 房屋列表中第一个房屋的发布日期 格式化后:<s:date name="houses[0].addDate" format="yyyy-MM-dd HH:mm:ss"/><br/> <s:property value="'<hr/>'" escapeHtml="false"/><br/> <!--s:set标签 --> 房屋列表中第一个房屋的街道名称:<s:set var="s" value="houses[0].Street" /> <s:property value="#s.streetName"/><br/> 房屋列表中第一个房屋的街道ID:<s:property value="#s.streetId"/><br/> 房屋列表中第一个房屋的地区名称: <s:property value="houses[0].Street.District.districtId"/><br/> 房屋列表中第一个房屋的地区名称:<s:set var="d" value="#s.District" /> <s:property value="#d.districtName"/><br/> <br/> 房屋列表中第一个房屋的地区ID:<s:property value="#d.districtId"/><br/><br/> <s:property value="'<hr/>'" escapeHtml="false"/><br/> <!--scope指定s:set var的取值 --> 房屋列表中第一个房屋的街道名称:<s:set var="s" value="houses[0].Street" scope="request" /> <s:property value="#request.s.streetName"/><br/> 房屋列表中第一个房屋的街道ID:<s:property value="#request.s.streetId"/><br/> <s:property value="'<hr/>'" escapeHtml="false"/><br/> 房屋列表中第一个房屋的地区名称:<s:set var="d" value="houses[0].Street.District" scope="session"/> <s:property value="#session.d.districtName"/><br/> 房屋列表中第一个房屋的地区ID:<s:property value="#session.d.districtId"/><br/> <s:debug/><br/> </body> </html>
地址栏输入：http://localhost:8080/OGNLDemo2/house.action发生跳转
三、s:a与s:url
<s:url var="house" value="house.action"> <!-- 传递参数 name为参数名称 vaule为要传的值 --> <s:param name="str" value="'struts2'"/> </s:url> <!-- 使用%{}来获取值--> <s:a href="%{#house}">跳转列表页面</s:a> <!--动态包含 --> <s:include value="include.jsp"></s:include>
四、控制标签
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@ taglib prefix="s" uri="/struts-tags"%> <% //绝对路径 String path = request.getContextPath(); String basePath = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort() + path + "/"; %> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <!-- 引入绝对路径 --> <base href="<%=basePath%>"> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>房屋列表信息</title> <style type="text/css"> .header{ text-align: center; background-color: #999999; font-weight: bold; font-size: 18px; } .even { text-align: center; background-color: #FFCCFF; } .odd { text-align: center; background-color: #CCCCFF; } </style> </head> <body> <table border="1" width="100%"> <tr class="header"> <td>房屋编号</td> <td>房屋标题</td> <td>房屋描述</td> <td>房屋发布日期</td> <td>房屋街道ID</td> <td>房屋街道</td> <td>房屋街道地区ID</td> <td>房屋街道地区名称</td> </tr> <s:iterator var="hou" value="houses" status="status"> <s:if test="#status.even"> <tr class="even"> </s:if> <s:if test="#status.odd"> <tr class="odd"> </s:if> <!-- 定义街道 --> <s:set var="strtmp" value="#hou.Street" /> <!--定义地区 --> <s:set var="distmp" value="#strtmp.District" /> <td><s:property value="#hou.houseId" /></td> <td><s:property value="#hou.title" /></td> <td><s:property value="#hou.desc" /></td> <td><s:date name="#hou.addDate" format="yyyy-MM-dd HH:mm:ss" /></td> <td><s:property value="#strtmp.streetId" /></td> <td><s:property value="#strtmp.streetName" /></td> <td><s:property value="#distmp.districtId" /></td> <td><s:property value="#distmp.districtName" /></td> </tr> </s:iterator> </table> <s:debug /> </body> </html>
struts.xml
<action name="house2" class="com.pb.web.action.HouseAction"> <result name="success"> /houseList2.jsp </result> </action>
地址栏中输入：http://localhost:8080/OGNLDemo2/house2.action访问
