常用的Web元素有：request、session、application等，而我們一般使用session較多，Struts2如何訪問web元素呢？這個是非常重要的內容，因為它能完成程序後台和用戶的數據交互，下面以註冊為例演示其過程：
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/> 密碼：<input type="text" name="user.password"></input> <br/> <input type="submit" value="註冊"/> </form> </body> </html>
功能很簡單--即用戶輸入用戶名和密碼，然後後台可以獲得，然後註冊成功後顯示給用戶
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>
可以有兩種方式完成這個功能
3、第一種（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; } }這個方式是用ActionContext.getContext()方法獲得context，然後得到request和session以及application
4、另外一種方式（UserAction02）非常常見，也是非常著名的方式-----Ioc（控制反轉）和DI（依賴注入），它需要實現3個接口如下：
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; } }這樣就實現了一個功能--將user的名稱和密碼都放入request中，在使用時我們只需取出即可
5、success.jsp將request中內容取出並顯示
<%@ 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>成功註冊</h3> <s:property value="#request.name"/>註冊成功，密碼為：<s:property value="#request.password"/> </body> </html>
其結果顯示為：
以上就是Struts2中訪問Web元素的全部內容，希望能給大家一個參考，也希望大家多多支持武林網。