Struts2之Ognl用法

OgnlAction.java

package com.kaishengit.web;

import java.util.HashMap;
import java.util.List;
import java.util.Map;

import com.kaishengit.dao.UserDao;
import com.kaishengit.vo.User;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;

public class OgnlAction extends ActionSupport {
    private int id;
    private String address;
    private Map<String,User> userMap;
    private User user;
    private List<User> userList;
    
    private UserDao dao=new UserDao();
    
    private static final long serialVersionUID = 5838762467757449050L;

    @SuppressWarnings("unchecked")
    public String execute() throws Exception{
        user=dao.findById("1");
        userList=dao.findAll();
        id=12;
        address="China";
        
        userMap=new HashMap<String,User>();
        userMap.put("tom", user);
        userMap.put("jerry", dao.findById("2"));
        
        Map<String,Object> session=ActionContext.getContext().getSession();
        session.put("sessionKey", "sessionValue");
        
        Map<String,Object> application=ActionContext.getContext().getParameters();
        application.put("applicationKey", "applicationValue");
        
        Map<String,Object> request=(Map<String, Object>) ActionContext.getContext().get("request");
        request.put("requestKey", "requestValue");
        
        
        return SUCCESS;
    }

    

    
    

    //-------------------------------------
    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }


    public User getUser() {
        return user;
    }

    public void setUser(User user) {
        this.user = user;
    }

    public List<User> getUserList() {
        return userList;
    }

    public void setUserList(List<User> userList) {
        this.userList = userList;
    }

    public Map<String, User> getUserMap() {
        return userMap;
    }

    public void setUserMap(Map<String, User> userMap) {
        this.userMap = userMap;
    }

    
}

struts.xml

    <action name="ognl" class="com.kaishengit.web.OgnlAction">
         <result>ognl.jsp</result>
    </action>

ognl.jsp

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@ taglib prefix="s" uri="/struts-tags" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <title></title>
    <meta http-equiv="pragma" content="no-cache">
    <meta http-equiv="cache-control" content="no-cache">
    <meta http-equiv="expires" content="0">    
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    <meta http-equiv="description" content="This is my page">
  </head>
  
  <body>
    ognl.jsp.....................<br>
      编号: <s:property value="id"/><br>
      地址:<s:property value="address"/><br>
  User对象:<s:property value="user"/><br>
  userName:<s:property value="user.userName"/><br>
  userPwd:<s:property value="user.userPwd"/><br>
  userList集合:<s:property value="userList"/><br>
  list size:<s:property value="userList.size"/><br>
 第一个对象：<s:property value="userList[0]"/><br>
  投影<br> 
 取得List中所有的姓名:<s:property value="userList.{userName}"/><br>
  取得List中第一个对象的姓名:<s:property value="userList.{userName}[0]"/>  
 输出List中姓名为tom的所有用户对象:<br>
  <s:property value="userList.{?#this.userName=='tom'}"/><br>
 输出List中姓名为tom的第一个用户对象:<br>
  <s:property value="userList.{^#this.userName=='tom'}"/><br>
 输出List中姓名为tom的最后一个用户对象：<br>
  <s:property value="userList.{$#this.userName=='tom'}"/><br>
  
  OGNL操作Map集合--------------------<br>
  输出Map中的key:<s:property value="userMap.keys"/><br>
 输出Map中的value:<s:property value="userMap.values"/><br>
输出Map中的数量:<s:property value="userMap.size"/><br>
输出key(tom)对应的value:<s:property value="userMap['tom'].{id}[0]"/><br>---
判断Map是否为empty:<s:property value="userMap.isEmpty"/><br>
动态创建List和Map ---------------------------<br>
动态创建List:<s:property value="{'aa','bb','cc'}"/>
动态创建Map:<s:property value="#{'aa':'aa','bb':'bb'}"/>
<br>
获取request  session  Application中的值--------------------------<br> 
获取Session中的值：<br>
<s:property value="#session.sessionKey"/><br>
获取reuqst中的值:<br>
<s:property value="#request.requestKey"/><br>
获取Application中的值:<br>
<s:property value="#application.applicationKey"/>
  </body>
</html>