常用的Web元素有：request、session、application等，而我们一般使用session较多，Struts2如何访问web元素呢？这个是非常重要的内容，因为它能完成程序后台和用户的数据交互，下面以注册为例演示其过程：
1、index.jsp文件
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <% 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> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <base href="<%=basePath %>"/> <title>Insert title here</title> </head> <body> <h1>演示</h1> <form action="user/user02!register" method="post"> 姓名：<input type="text" name="user.name"></input> <br/> 密码：<input type="text" name="user.password"></input> <br/> <input type="submit" value="注册"/> </form> </body> </html>
功能很简单--即用户输入用户名和密码，然后后台可以获得，然后注册成功后显示给用户
2、struts.xml 配置
<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN" "http://struts.apache.org/dtds/struts-2.0.dtd"> <struts> <constant name="struts.devMode" value="true" /> <package name="front" namespace="/user" extends="struts-default"> <action name="user*"> <result>/success.jsp</result> <result name="error">/error.jsp</result> </action> </package> </struts>
可以有两种方式完成这个功能
3、第一种（UserAction01）
package com.myservice.web; import java.util.Map; import com.opensymphony.xwork2.ActionContext; import com.opensymphony.xwork2.ActionSupport; public class UserAction01 extends ActionSupport { /** * */ private static final long serialVersionUID = 1L; private User user; private Map request; private Map session; private Map application; public UserAction01(){ request = (Map)ActionContext.getContext().get("request"); session = ActionContext.getContext().getSession(); application = ActionContext.getContext().getApplication(); } public String register(){ request.put("name", user.getName()); request.put("password", user.getPassword()); return SUCCESS; } public User getUser() { return user; } public void setUser(User user) { this.user = user; } } 这个方式是用ActionContext.getContext()方法获得context，然后得到request和session以及application
4、另外一种方式（UserAction02）非常常见，也是非常著名的方式-----Ioc（控制反转）和DI（依赖注入），它需要实现3个接口如下：
package com.myservice.web; import java.util.Map; import org.apache.struts2.interceptor.ApplicationAware; import org.apache.struts2.interceptor.RequestAware; import org.apache.struts2.interceptor.SessionAware; import com.opensymphony.xwork2.ActionSupport; public class UserAction02 extends ActionSupport implements RequestAware, SessionAware,ApplicationAware{ private Map<String, Object> request; private Map<String, Object> session; private Map<String, Object> application; private User user; public User getUser() { return user; } public void setUser(User user) { this.user = user; } public String register(){ request.put("name", user.getName()); request.put("password", user.getPassword()); return SUCCESS; } @Override public void setApplication(Map<String, Object> application) { // TODO Auto-generated method stub this.application = application; } @Override public void setSession(Map<String, Object> session) { // TODO Auto-generated method stub this.session = session; } @Override public void setRequest(Map<String, Object> request) { // TODO Auto-generated method stub this.request = request; } }这样就实现了一个功能--将user的名称和密码都放入request中，在使用时我们只需取出即可
5、success.jsp将request中内容取出并显示
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@taglib uri="/struts-tags" prefix="s" %> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Insert title here</title> </head> <body> <h3>成功注册</h3> <s:property value="#request.name"/>注册成功，密码为：<s:property value="#request.password"/> </body> </html>
其结果显示为：
以上就是Struts2中访问Web元素的全部内容，希望能给大家一个参考，也希望大家多多支持武林网。