Struts2(七) Struts2访问Servlet的API

当接受表单参数,向页面保持数据时。要用到Struts访问Servlet 的API 。下面只做参考,有错误或不同意见可以发送邮箱[email protected]  。建议大家看struts文档,源代码 

1.struts2通过ActionContext访问

com.opensymphony.xwork2.ActionContext;类有很多方法这里只列举几个常用的方法;

Struts2(七) Struts2访问Servlet的API_第1张图片

Struts2(七) Struts2访问Servlet的API_第2张图片

列举个小例子

Struts2的核心配置web.xml 就不做说明了  。前面已经操作过;

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>
    
    
    <constant name="struts.i18n.encoding" value="UTF-8">constant>
    <constant name="struts.devMode " value="true">constant>
    <constant name="struts.action.extension" value="action,,">constant>
        
    <package name="hello"  namespace="/" extends="struts-default">
         
         <action  name="Demo1"  class="com.sturts2.day02.action.RequestDemo1">
                 <result name="success">/demo2.jspresult>
         action>
    package>
struts>

RequestDemo1.java      Action类

 1 public class RequestDemo1  extends ActionSupport{
 2     @Override
 3     public String execute() throws Exception {
 4         //ac 相当于Servlet 的request
 5                 ActionContext ac=ActionContext.getContext();
 6                 Map paramMap=ac.getParameters();
 7                 for(String key: paramMap.keySet()){
 8                     String [] value=(String[]) paramMap.get(key);
 9                     System.out.println(key+"  "+value[0]);
10                 }
11                 
12                 ac.put("request1", "张三");
13                 ac.getSession().put("session1","李四");
14                 ac.getApplication().put("application1", "王五");    
15         return SUCCESS;
16     }
17 }

demo1.jsp

<body>
    <h1>访问Servlet API 方式之一h1>
    <form action="${pageContext.request.contextPath}/Demo1.action" method="post">
        姓名:<input type="text" name="name"><br/>
        年龄:<input type="text" name="age"><br/>
        <input type="submit" value="提交">
    form>
body>

demo2.jsp

<body>
     <h1>获取数据h1>
    requet:  ${request1 } <br/><br/>
    session:    ${session1 } <br/><br/>
    application:  ${application1 } <br/><br/>
body>

在服务器上运行 ,打开demo1 :

Struts2(七) Struts2访问Servlet的API_第3张图片

输入数据提交表单: 控制台显示

 

 浏览器跳转页面:

Struts2(七) Struts2访问Servlet的API_第4张图片

 

 2.通过特定接口访问

Struts2 的ActionContext访问Servlet API  无法直接获得Servlet  API 实例。以下接口可以直接访问Servlet  API ;

  • ServletRequestAware  :实现该接口的Action可以直接访问web应用的HttpServletRequest
  • ServletResponseAware  :实现该接口的Action可以直接访问web应用的HttpServletResponse
  • SessionAware :实现该接口的Action可以直接访问web应用的TttpSession
  • ServletContextAware  :实现该接口的Action可以直接访问web应用的ServletContex实例
 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 <struts>
 6     <package name="api"  namespace="/" extends="struts-default">
 7     
 8          <action  name="Demo5Action"  class="com.sturts2.day02.b_api.Demo5Action">
 9                  <result name="success" >/api.jspresult>
10          action>
11         
12     package>
13 struts>

 

3.通过ServletActionContext访问

借助ServletActionContext 类,避免action实现ServletRequestAware  ,ServletResponseAware、SessionAware 和ServletContextAware 等 XxxAware接口。但Action直接与ServletAPI耦合,不利于程序的解耦。建议使用ActionContext

代码如下:

  • static HttpServletResquest getRequest();  获取Web应用HttpServletResquest对象
  • static HttpServletResponse getResponse();  获取Web应用HttpServletResponse对象
  • static ServletContext  getServletContext();    获取Web应用ServletContext对象
  • static PageContext getPageContext();       获取Web应用pageContext对象

struts.xml配置

 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 <struts>
 6     <package name="api"  namespace="/" extends="struts-default">
 7     
 8          <action  name="Demo5Action"  class="com.sturts2.day02.b_api.Demo5Action">
 9                  <result name="success" >/api.jspresult>
10          action>
11          
12                  
13        
14     package>
15 struts>

 Action类

package com.sturts2.day02.b_api;

import javax.servlet.http.HttpServletRequest;

import org.apache.struts2.interceptor.ServletRequestAware;

import com.opensymphony.xwork2.ActionSupport;

public class Demo5Action  extends  ActionSupport  implements ServletRequestAware {
    private HttpServletRequest request;
    @Override
    public String execute() throws Exception {
        System.out.println("原生request:"+request);
        return SUCCESS;
    }


    @Override
    public void setServletRequest(HttpServletRequest request) {
        this.request=request;
    }
    
}

api.jsp

1 <body>
2     request:${request1 } <br/>
3     session:${session1 }   <br/>
4     application:${application1 } <br/>
5     
6 body>

页面显示:

Struts2(七) Struts2访问Servlet的API_第5张图片

控制台输出

 

你可能感兴趣的:(Struts2(七) Struts2访问Servlet的API)