struts2 访问Web元素的4种方法

第一种也是最常用的一种方法实现这几个接口

RequestAware,SessionAware,ApplicationAware

struts以依赖注入方式把request，session和application赋上值，看一下完整的代码

package com.pengli.struts.parampack;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 MyWinAction2 extends ActionSupport  implements RequestAware,SessionAware,ApplicationAware{    static int actionCount=0;    private Map<String, Object> my_Request;    private Map<String, Object> session;    private Map<String, Object> application;            public String add()    {        AddKey();        return "add";    }        @Override    public void setRequest(Map<String, Object> arg0) {        // TODO Auto-generated method stub        my_Request=arg0;    }    @Override    public void setApplication(Map<String, Object> arg0) {        // TODO Auto-generated method stub        application=arg0;    }    @Override    public void setSession(Map<String, Object> arg0) {        // TODO Auto-generated method stub        session = arg0;    }    private void AddKey()    {        ++actionCount;        my_Request.put("a1", "Two"+actionCount);        ++actionCount;        session.put("a2", "Two"+actionCount);        ++actionCount;        application.put("a3", "Two"+actionCount);    }    }

第二种方式是实现ServletRequestAware接口

得到request接口后，再根据 request的方法去得到session和application

package com.pengli.struts.parampack;import javax.servlet.ServletContext;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpSession;import org.apache.struts2.interceptor.ServletRequestAware;import org.apache.struts2.util.ServletContextAware;import com.opensymphony.xwork2.ActionSupport;public class MyWinAction3 extends ActionSupport implements ServletRequestAware {    private HttpServletRequest request;        private HttpSession session;    private ServletContext application;        public String add()    {        setAttribute();        return "add";    }        @Override    public void setServletRequest(HttpServletRequest arg0) {        // TODO Auto-generated method stub        request=arg0;        session=request.getSession();        application=session.getServletContext();            }                private void setAttribute()    {        request.setAttribute("a1", "ThreeA1");        session.setAttribute("a2", "ThreeA2");        application.setAttribute("a3", "ThreeA3");    }}

第三种方式和第二种有点像，是用ServletActionContext得到request再得到sesion和application

package com.pengli.struts.parampack;import javax.servlet.ServletContext;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpSession;import org.apache.struts2.ServletActionContext;import com.opensymphony.xwork2.ActionSupport;public class MyWinAction4 extends ActionSupport{    private HttpServletRequest request;        private HttpSession session;    private ServletContext application;        public String add(){                getInfo();        setAttribute();                return "add";    }        private void getInfo()    {        request = ServletActionContext.getRequest();        session = request.getSession();        application = session.getServletContext();    }        private void setAttribute()    {        request.setAttribute("a1", "FourA1");        session.setAttribute("a2", "FourA2");        application.setAttribute("a3", "FourA3");    }}

最后一种方法是通过ActionContext得到相应的参数

 

package com.pengli.struts.parampack;import java.util.Map;import com.opensymphony.xwork2.ActionContext;import com.opensymphony.xwork2.ActionSupport;public class MyWiAction extends ActionSupport {        private UserModel user;    public  String add1()    {        if(user == null)        {            this.addFieldError("user", "user object is null");            return ERROR;        }        if(user.getName()== null||user.getAge() == null)        {            this.addFieldError("name", "name is null");            this.addFieldError("age", "age is null");            return ERROR;        }        System.out.println(user.getAge());        System.out.println(user.getName());        return "add1";    }    static int actionCount=0;    private Map request1;    private Map session1;    private Map application1;        public String add()    {        request1 = (Map)ActionContext.getContext().get("request");        session1=ActionContext.getContext().getSession();        application1 = ActionContext.getContext().getApplication();                AddKey();                return "add";    }        @Override    public String execute() throws Exception {        // TODO Auto-generated method stub                return super.execute();    }        public String add2()    {        return "add2";    }        public String add3()     {        return "add3";    }            private void AddKey()    {        ++actionCount;        request1.put("a1", "a1haha"+actionCount);            ++actionCount;        session1.put("a2", "a2haha"+actionCount);            ++actionCount;        application1.put("a3", "a3haha"+actionCount);    }    public String edit()    {        return "edit";    }    public UserModel getUser() {        return user;    }    public void setUser(UserModel user) {        this.user = user;    }}

再看一下web页面如何访问这些元素

<%@ page language="java" import="java.util.*" pageEncoding="GB18030"%><%String path = request.getContextPath();String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";%><%@ taglib uri="/struts-tags" prefix="s" %><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html>  <head>    <base href="<%=basePath%>">        <title>My JSP 'Oneaddok.jsp' starting page</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">    <!--    <link rel="stylesheet" type="text/css" href="styles.css">    -->  </head>    <body>    This is my JSP page. <br>    <s:property value="#request.a1" />|<%= request.getAttribute("a1") %> <br/>    <s:property value="#session.a2" />|<%= session.getAttribute("a2") %> <br/>    <s:property value="#application.a3" />|<%= application.getAttribute("a3") %> <br/>  </body></html>

再看一下struts.xml

<?xml version="1.0" encoding="UTF-8" ?><!DOCTYPE struts PUBLIC    "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"    "http://struts.apache.org/dtds/struts-2.3.dtd"><struts>    <!-- Add packages here -->     <constant name="struts.devMode" value="true" />    <constant name="struts.enable.DynamicMethodInvocation" value="true"/>    <package name="default1" namespace="/" extends="struts-default">                <action name="One*1" class="com.pengli.struts.parampack.MyWiAction" method="{1}">            <result name ="{1}">                /Oneaddok.jsp            </result>                    <result name="error">                /errorpage.jsp            </result>            </action>        <action name="One*2" class="com.pengli.struts.parampack.MyWinAction2" method="{1}">            <result name ="{1}">                /Oneaddok.jsp            </result>                    <result name="error">                /errorpage.jsp            </result>            </action>        <action name="One*3" class="com.pengli.struts.parampack.MyWinAction3" method="{1}">            <result name ="{1}">                /Oneaddok.jsp            </result>                    <result name="error">                /errorpage.jsp            </result>            </action>        <action name="One*4" class="com.pengli.struts.parampack.MyWinAction4" method="{1}">            <result name ="{1}">                /Oneaddok.jsp            </result>                    <result name="error">                /errorpage.jsp            </result>            </action>    </package></struts>