web12 使用map型的request、session、application

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通過ActionContext對象擷取map類型的request、session、application，分别為這3個對象設定一個info屬性并指派，然後在jsp頁面擷取3種作用域下的info屬性資訊。

1、建立web項目，jwrm05-mapRequest,拷貝包到lib，配置web.xm。（詳見web08）

2、建立類TestAction

package dog;

import java.util.Map;

import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;

public class TestAction extends ActionSupport {
    private static final long serialVersionUID=1L;
    
    //map類型的request
    private Map<String,Object>request;
    //map類型的session
    private Map<String,Object>session;
    //map類型的application
    private Map<String,Object>application;
    
    //構造方法
    @SuppressWarnings("unchecked")
    public TestAction(){
        //擷取ActionContext對象
        ActionContext context=ActionContext.getContext();
        
        //擷取Map類型的request
        request=(Map<String,Object>)context.get("request");
        //擷取Map類型的session
        session=context.getSession();
        //擷取Map類型的application
        application=context.getApplication();
    }
    
    /*
     * 請求處理方法
     * return String
     */
    public String execute() throws Exception{
        
        //字元串資訊
        String info="星網：www.aikan66.com";
        
        //向request添加資訊
        request.put("info", info);
        
        //向Session添加資訊
        session.put("info", info);
        
        //向application添加資訊
        application.put("info", info);
        //成功傳回
        return SUCCESS;
    }
}

3、配飾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>
    <!-- 聲明包 -->
    <package name="myPackage" extends="struts-default">
        <!-- 定義action -->
        <action name="testAction" class="dog.TestAction">
            <!-- 定義成功的映射頁面 -->
            <result>success.jsp</result>
        </action>
    </package> 
</struts>

4、建立success.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<%@ taglib prefix="s" uri="/struts-tags" %>  
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>My JSP 'success.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>
    request範圍内的info值：
    <font color="red"><%=request.getAttribute("info") %></font><br>
    session範圍内的info值：
    <font color="red"><%=session.getAttribute("info")%></font><br>
    application範圍内info值：
    <font color="red"><%=application.getAttribute("info") %></font>
  </body>
</html>

index.jsp中添加

<%@ page language="java" import="java.util.*" 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">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>My JSP 'index.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>
    <a href="testAction.action">Map類型的request、session、application</a>
  </body>
</html>

5、部署，通路：http://localhost:8080/jwrm05-mapRequest/index.jsp

點選，結果

完畢

<?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">

<result>success.jsp</result>

</action>

</package>

</struts>