Struts2获取web对象的4种方式

2016-03-15 20:00 134人阅读 评论(0) 收藏 举报

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Struts2（3） 

版权声明：本文为博主原创文章，转载请指明 http://blog.csdn.net/tanggao1314/

目录(?)[-]

1. Struts2获取web对象的4种方式
   1. 一通过ServletActionContext取HttpServletRequest对象
   2. 二通过ServletRequestAwareServletResponseAware 来注入HttpServletRequestHttpServletResponse对象
   3. 三通过ActionContext取Map
   4. 四通过RequestAwareSessionAwareApplicationAware接口来注入  三个Map

Struts2获取web对象的4种方式

Struts2是如何获取web中 request、session、application的了，Struts2有4种方式获取web对象

1.通过ServletActionContext取HttpServletRequest对象

2.通过ServletRequestAware，(ServletResponseAware )来注入HttpServletRequest、(HttpServletResponse)对象

3.通过ActionContext取Map

4.通过RequestAware,SessionAware,ApplicationAware接口，来注入  三个Map

下面的例子就用以上4种方式来实现如何获取web对象

首先建立一个实体类,接收从客户端传过来的参数,通过ModelDriven，如果对传递参数不明白的可以参看我上篇文章三种对象传参和ModelDriven的原理

一个Student实体类

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1. package com.yc.web.actions;  
2.   
3. import java.io.Serializable;  
4.   
5. public class Student implements Serializable {  
6.     private static final long serialVersionUID = -6646865822958505769L;  
7.     private String name;  
8.     private Integer age;  
9.     public String getName() {  
10.         return name;  
11.     }  
12.     public void setName(String name) {  
13.         this.name = name;  
14.     }  
15.     public Integer getAge() {  
16.         return age;  
17.     }  
18.     public void setAge(Integer age) {  
19.         this.age = age;  
20.     }  
21. }  

一、通过ServletActionContext取HttpServletRequest对象

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1. package com.yc.web.actions;  
2.   
3. import javax.servlet.ServletContext;  
4. import javax.servlet.http.HttpServletRequest;  
5. import javax.servlet.http.HttpServletResponse;  
6. import javax.servlet.http.HttpSession;  
7.   
8. import org.apache.struts2.ServletActionContext;  
9.   
10. import com.opensymphony.xwork2.Action;  
11. import com.opensymphony.xwork2.ActionSupport;  
12. import com.opensymphony.xwork2.ModelDriven;  
13.   
14. public class StudentAction extends ActionSupport implements ModelDriven<Student>{  
15.     private static final long serialVersionUID = 1213446993015542840L;  
16.     private Student student;  
17.     private HttpServletRequest request;  
18.     private HttpSession session;  
19.     private ServletContext application;  
20.     private HttpServletResponse response;  
21.       
22.     public  StudentAction() {  
23.         //获取web对象  
24.         request=ServletActionContext.getRequest();  
25.         session=request.getSession();  
26.         application=session.getServletContext();  
27.     }  
28.     public String execute(){  
29.         //赋值  
30.         request.setAttribute("student", student);  
31.         session.setAttribute("student", student);  
32.         application.setAttribute("student", student);  
33.         return Action.SUCCESS;  
34.     }  
35.     @Override  
36.     public Student getModel() {  
37.         student =new Student();  
38.         return student;  
39.     }  
40. }  

二、通过ServletRequestAware(ServletResponseAware )来注入HttpServletRequest(HttpServletResponse)对象

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1. package com.yc.web.actions;  
2.   
3. import javax.servlet.ServletContext;  
4. import javax.servlet.http.HttpServletRequest;  
5. import javax.servlet.http.HttpServletResponse;  
6. import javax.servlet.http.HttpSession;  
7.   
8. import org.apache.struts2.ServletActionContext;  
9. import org.apache.struts2.interceptor.ServletRequestAware;  
10. import org.apache.struts2.interceptor.ServletResponseAware;  
11.   
12. import com.opensymphony.xwork2.Action;  
13. import com.opensymphony.xwork2.ActionSupport;  
14. import com.opensymphony.xwork2.ModelDriven;  
15.   
16. public class StudentAction2 extends ActionSupport implements   
17. ModelDriven<Student> ,ServletRequestAware,ServletResponseAware{  
18.     private static final long serialVersionUID = 1213446993015542840L;  
19.     private Student student;  
20.     private HttpServletRequest request;  
21.     private HttpSession session;  
22.     private ServletContext application;  
23.     private HttpServletResponse response;  
24.       
25.     @Override  
26.     public Student getModel() {  
27.         student =new Student();  
28.         return student;  
29.     }  
30.     @Override  
31.     public void setServletResponse(HttpServletResponse arg0) {  
32.         //获取response对象  
33.         response=arg0;  
34.     }  
35.   
36.     @Override  
37.     public void setServletRequest(HttpServletRequest arg0) {  
38.         //获取web对象  
39.         request=arg0;  
40.         session=request.getSession();  
41.         application=session.getServletContext();  
42.     }  
43.       
44.     public String execute(){  
45.         //赋值  
46.         request.setAttribute("student", student);  
47.         session.setAttribute("student", student);  
48.         application.setAttribute("student", student);  
49.         return Action.SUCCESS;  
50.           
51.     }  
52. }  

三、通过ActionContext取Map

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1. package com.yc.web.actions;  
2.   
3. import java.util.Map;  
4.   
5. import javax.servlet.ServletContext;  
6. import javax.servlet.http.HttpServletRequest;  
7. import javax.servlet.http.HttpServletResponse;  
8. import javax.servlet.http.HttpSession;  
9.   
10. import org.apache.struts2.ServletActionContext;  
11. import org.apache.struts2.interceptor.ServletRequestAware;  
12. import org.apache.struts2.interceptor.ServletResponseAware;  
13.   
14. import com.opensymphony.xwork2.Action;  
15. import com.opensymphony.xwork2.ActionContext;  
16. import com.opensymphony.xwork2.ActionSupport;  
17. import com.opensymphony.xwork2.ModelDriven;  
18.   
19. public class StudentAction3 extends ActionSupport implements ModelDriven<Student>{  
20.     private static final long serialVersionUID = 1213446993015542840L;  
21.     private Student student;  
22.     private Map<String ,Object> request;  
23.     private Map<String ,Object> session;  
24.     private Map<String ,Object> application;  
25.     public  StudentAction3() {  
26.         //获取web对象  
27.         request=(Map<String, Object>) ActionContext.getContext().get("request");  
28.         session=ActionContext.getContext().getSession();  
29.         application=ActionContext.getContext().getApplication();  
30.     }  
31.     public String execute(){  
32.         //赋值  
33.         request.put("student", student);  
34.         session.put("student", student);  
35.         application.put("student", student);  
36.         return Action.SUCCESS;  
37.           
38.     }  
39.     @Override  
40.     public Student getModel() {  
41.         student =new Student();  
42.         return student;  
43.     }  
44. }  

四、通过RequestAware,SessionAware,ApplicationAware接口，来注入  三个Map

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1. package com.yc.web.actions;  
2.   
3. import java.util.Map;  
4.   
5. import javax.servlet.ServletContext;  
6. import javax.servlet.http.HttpServletRequest;  
7. import javax.servlet.http.HttpServletResponse;  
8. import javax.servlet.http.HttpSession;  
9.   
10. import org.apache.struts2.ServletActionContext;  
11. import org.apache.struts2.interceptor.ApplicationAware;  
12. import org.apache.struts2.interceptor.RequestAware;  
13. import org.apache.struts2.interceptor.ServletRequestAware;  
14. import org.apache.struts2.interceptor.ServletResponseAware;  
15. import org.apache.struts2.interceptor.SessionAware;  
16.   
17. import com.opensymphony.xwork2.Action;  
18. import com.opensymphony.xwork2.ActionSupport;  
19. import com.opensymphony.xwork2.ModelDriven;  
20.   
21. import freemarker.template.utility.Execute;  
22.   
23. public class StudentAction4 extends ActionSupport implements   
24. ModelDriven<Student> ,RequestAware,SessionAware,ApplicationAware{  
25.     private static final long serialVersionUID = 1213446993015542840L;  
26.     private Student student;  
27.     private Map<String ,Object> request;  
28.     private Map<String ,Object> session;  
29.     private Map<String ,Object> application;  
30.       
31.     public String execute(){  
32.         //赋值  
33.         request.put("student", student);  
34.         session.put("student", student);  
35.         application.put("student", student);  
36.         return Action.SUCCESS;  
37.           
38.     }  
39.       
40.     @Override  
41.     public Student getModel() {  
42.         student =new Student();  
43.         return student;  
44.     }  
45.     //获取web对象  
46.     @Override  
47.     public void setApplication(Map<String, Object> arg0) {  
48.         application=arg0;  
49.     }  
50.     @Override  
51.     public void setSession(Map<String, Object> arg0) {  
52.         session=arg0;  
53.           
54.     }  
55.     @Override  
56.     public void setRequest(Map<String, Object> arg0) {  
57.         request=arg0;  
58.     }  
59. }  

下面是访问页面 index,jsp

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1. <%@ page language="java" contentType="text/html; charset=UTF-8"  
2.     pageEncoding="UTF-8"%>  
3. <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">  
4. <html>  
5. <head>  
6. <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">  
7. <title>Insert title here</title>  
8. </head>  
9. <body>  
10.   
11. </body>  
12.     <a href="student.action?name=tg&age=20">学生 </a>  
13.     <a href="student2.action?name=tg&age=20">学生 </a>  
14.     <a href="student3.action?name=tg&age=20">学生 </a>  
15.     <a href="student4.action?name=tg&age=20">学生 </a>  
16. </html>  

下面struts.xml

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1. <?xml version="1.0" encoding="UTF-8" ?>  
2. <!DOCTYPE struts PUBLIC  
3.     "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"  
4.     "http://struts.apache.org/dtds/struts-2.3.dtd">  
5.   
6. <struts>  
7.   
8.     <constant name="struts.enable.DynamicMethodInvocation" value="false" />  
9.     <constant name="struts.devMode" value="true" />  
10.     <constant name="struts.action.extension" value="action,do,,"/>  
11.       
12.     <package name="default" namespace="/" extends="struts-default">  
13.   
14.       <action name="student" class="com.yc.web.actions.StudentAction">  
15.         <result name="success">/show.jsp</result>   
16.       </action>  
17.         
18.        <action name="student2" class="com.yc.web.actions.StudentAction2">  
19.         <result name="success">/show.jsp</result>   
20.       </action>  
21.         
22.        <action name="student3" class="com.yc.web.actions.StudentAction3">  
23.         <result name="success">/show.jsp</result>  
24.       </action>  
25.         
26.        <action name="student4" class="com.yc.web.actions.StudentAction4">  
27.         <result name="success">/show.jsp</result>  
28.       </action>  
29.         
30.       <action name="student4" class="com.yc.web.actions.StudentAction4">  
31.         <result name="success">/show.jsp</result>  
32.       </action>  
33.     </package>  
34.   
35. </struts>  

访问成功显示页面show.jsp

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1. <%@ page language="java" contentType="text/html; charset=UTF-8"  
2.     pageEncoding="UTF-8"%>  
3. <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">  
4. <html>  
5. <head>  
6. <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">  
7. <title>Insert title here</title>  
8. </head>  
9. <body>  
10.     ${requestScope.student.name}   -${requestScope.student.age}  <br/>  
11.     ${sessionScope.student.name}   -${sessionScope.student.age} <br/>   
12.     ${applicationScope.student.name} -${applicationScope.student.age}  <br/>  
13. </body>  
14. </html>