Struts访问web元素

//index.jsp

 1 <?xml version="1.0" encoding="GB18030" ?>
 2 <%@ page language="java" contentType="text/html; charset=GB18030"
 3     pageEncoding="GB18030"%>
 4 
 5 <% String context = request.getContextPath(); %>
 6 
 7 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
 8 <html xmlns="http://www.w3.org/1999/xhtml">
 9 <head>
10 <meta http-equiv="Content-Type" content="text/html; charset=GB18030" />
11 <title>Insert title here</title>
12 </head>
13 <body>
14 取得Map类型request,session,application,真实类型 HttpServletRequest, HttpSession, ServletContext的引用:
15 <ol>
16     <li>前三者：依赖于容器</li>
17     <li>前三者：IOC</li> (只用这种)
18     <li>后三者：依赖于容器</li>
19     <li>后三者：IOC</li>
20 </ol>
21 <br />
22 
23 <!-- 定义一个表单 提交用户名和密码 -->
24 
25 <form name="f" action="" method="post">
26 用户名：<input type="text" name="name"/>
27 密码：<input type="text" name="password"/>
28 <br />
29 
30 <!-- 通过javascript:document.f.action动态提交到不同的action中进行不同的处理  -->
31 <input type="button" value="submit1" onclick="javascript:document.f.action='login/login1';document.f.submit();" />
32 <input type="button" value="submit2" onclick="javascript:document.f.action='login/login2';document.f.submit();" />
33 <input type="button" value="submit3" onclick="javascript:document.f.action='login/login3';document.f.submit();" />
34 <input type="button" value="submit4" onclick="javascript:document.f.action='login/login4';document.f.submit();" />
35 </form>
36     
37 </body>
38 </html>

//struts.xml

 1 <?xml version="1.0" encoding="UTF-8" ?>
 2 <!DOCTYPE struts PUBLIC
 3     "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
 4     "http://struts.apache.org/dtds/struts-2.0.dtd">
 5 
 6 <struts>
 7     <constant name="struts.devMode" value="true" />
 8     <package name="login" extends="struts-default" namespace="/login">
 9         <!-- 使用通配符分别对应传入的login1,2,3,4 并调用不同的class -->
10         <action name="login*" class="com.bjsxt.struts2.user.action.LoginAction{1}">
11             <result>/user_login_success.jsp</result>
12         </action>
13     </package>
14 </struts>

//方法1

 1 package com.bjsxt.struts2.user.action;
 2 
 3 import java.util.Map;
 4 
 5 import com.opensymphony.xwork2.ActionContext;
 6 import com.opensymphony.xwork2.ActionSupport;
 7 
 8 
 9 //第一种可以取得request的方式
10 //称之为
11 public class LoginAction1 extends ActionSupport {
12     
13     private Map request;
14     private Map session;
15     private Map application;
16     
17     public LoginAction1() {
18         //ActionContext.getContext取得action中的上下文 对应JSP的为Application
19         //取得request的方法
20         request = (Map)ActionContext.getContext().get("request");
21         //取得Session的方法
22         session = ActionContext.getContext().getSession();
23         //取得Application的方法
24         application = ActionContext.getContext().getApplication();
25     }
26     
27     public String execute() {
28         //在得到的Map中放入值 查看前台是否能够访问
29         //这种处理方法即将这里设置的值全部复制到http内容中去
30         request.put("r1", "r1");
31         session.put("s1", "s1");
32         application.put("a1", "a1");
33         return SUCCESS; 
34     }
35     
36     
37 }

//方法2

 1 package com.bjsxt.struts2.user.action;
 2 
 3 import java.util.Map;
 4 
 5 import org.apache.struts2.interceptor.ApplicationAware;
 6 import org.apache.struts2.interceptor.RequestAware;
 7 import org.apache.struts2.interceptor.SessionAware;
 8 
 9 import com.opensymphony.xwork2.ActionContext;
10 import com.opensymphony.xwork2.ActionSupport;
11 
12 
13 //实现了3个接口,必须复写3个方法
14 //Aware:得知,获得.
15 //这是最常用的方式
16 public class LoginAction2 extends ActionSupport implements RequestAware,SessionAware, ApplicationAware {
17     private Map<String, Object> request;
18     private Map<String, Object> session;
19     private Map<String, Object> application;    
20     //DI dependency injection 依赖注入
21     //IoC inverse of control 控制翻转    
22     public String execute() {
23         request.put("r1", "r1");
24         session.put("s1", "s1");
25         application.put("a1", "a1");
26         return SUCCESS; 
27     }
28 
29     //实现了三个Aware接口后,Struts2将会将request,session和Application传来
30     @Override
31     public void setRequest(Map<String, Object> request) {
32         this.request = request;
33     }
34 
35     @Override
36     public void setSession(Map<String, Object> session) {
37         this.session = session;
38     }
39 
40     @Override
41     public void setApplication(Map<String, Object> application) {
42         this.application = application;
43     }
44     
45     
46 }

//方法3

 1 package com.bjsxt.struts2.user.action;
 2 
 3 import javax.servlet.ServletContext;
 4 import javax.servlet.http.HttpServletRequest;
 5 import javax.servlet.http.HttpSession;
 6 
 7 import org.apache.struts2.ServletActionContext;
 8 
 9 import com.opensymphony.xwork2.ActionSupport;
10 
11 //基本不用
12 public class LoginAction3 extends ActionSupport {
13     
14     private HttpServletRequest request;
15     private HttpSession session;
16     private ServletContext application;
17     
18     public LoginAction3() {
19         request = ServletActionContext.getRequest();
20         session = request.getSession();
21         application = session.getServletContext();
22     }
23     
24     public String execute() {
25         request.setAttribute("r1", "r1");
26         session.setAttribute("s1", "s1");
27         application.setAttribute("a1", "a1");
28         return SUCCESS; 
29     }
30     
31 }

//方法4

 1 package com.bjsxt.struts2.user.action;
 2 
 3 import javax.servlet.ServletContext;
 4 import javax.servlet.http.HttpServletRequest;
 5 import javax.servlet.http.HttpSession;
 6 
 7 import org.apache.struts2.interceptor.ServletRequestAware;
 8 
 9 import com.opensymphony.xwork2.ActionSupport;
10 
11 //基本不用
12 public class LoginAction4 extends ActionSupport implements ServletRequestAware {
13     
14     private HttpServletRequest request;
15     private HttpSession session;
16     private ServletContext application;
17     
18     
19     
20     public String execute() {
21         request.setAttribute("r1", "r1");
22         session.setAttribute("s1", "s1");
23         application.setAttribute("a1", "a1");
24         return SUCCESS; 
25     }
26 
27 
28 
29     @Override
30     public void setServletRequest(HttpServletRequest request) {
31         this.request = request;
32         this.session = request.getSession();
33         this.application = session.getServletContext();
34     }
35     
36 }

//显示取出的值

 1 <?xml version="1.0" encoding="GB18030" ?>
 2 <%@ page language="java" contentType="text/html; charset=GB18030"
 3     pageEncoding="GB18030"%>
 4     <%@taglib uri="/struts-tags" prefix="s" %>
 5 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
 6 <html xmlns="http://www.w3.org/1999/xhtml">
 7 <head>
 8 <meta http-equiv="Content-Type" content="text/html; charset=GB18030" />
 9 <title>Insert title here</title>
10 </head>
11 <body>
12     User Login Success!
13     <br />
14 
15     <!-- 用标签访问request中的值 -->
16     <s:property value="#request.r1"/> | <%=request.getAttribute("r1") %> <br />
17     <s:property value="#session.s1"/> | <%=session.getAttribute("s1") %> <br />
18     <s:property value="#application.a1"/> | <%=application.getAttribute("a1") %> <br />
19     <s:property value="#attr.a1"/><br />
20     <s:property value="#attr.s1"/><br />
21     <s:property value="#attr.r1"/><br />
22     <s:debug></s:debug>
23     <br />
24 </body>
25 </html>

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原文地址：https://www.cnblogs.com/elleniou/p/2724478.html