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