struts2 访问Web元素的4种方法

2023-07-18 16:51:16

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>

完整代码：Struts12AccessWebElement.rar

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