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
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<%@ 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>
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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
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<?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*" class="com.myservice.web.UserAction{1}">
<result>/success.jsp</result>
<result name="error">/error.jsp</result>
</action>
</package>
</struts>
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可以有两种方式完成这个功能
3、第一种（UserAction01）
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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;
}
}
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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：
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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;
}
}
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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
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<%@ 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>
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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服务器之家。