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> |
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 > |
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; } } |
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; } } |
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 > |
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。