//页面
    <h1>Servlet的API的访问方式一：解耦合的方式</h1>
    <form action="${ pageContext.request.contextPath }/requestDemo1.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>
  //action
      public class RequestDemo1Action extends ActionSupport{

      @Override
      public String execute() throws Exception {
        // 接收数据：
        /**
         * 在ActionContext中提供了一些方法:操作域对象的数据
         * 	* Map<String,Object> getParameters();
         * 	* Map<String,Object> getSession();
         *  * Map<String,Object> getApplication();
         */
        // 接收参数:
        ActionContext actionContext = ActionContext.getContext();
        Map<String,Object> map = actionContext.getParameters();
        for (String key : map.keySet()) {
          String[] arrs = (String[]) map.get(key);
          System.out.println(key+"    "+Arrays.toString(arrs));
        }
        // 向request域中存值：
        actionContext.put("reqName", "req如花");
        // 向session域中存值:
        actionContext.getSession().put("sessName", "sess凤姐");
        // 向application域中存值：
        actionContext.getApplication().put("appName","app石榴");
        return SUCCESS;
        }
      }

  //页面
    <h1>Servlet的API的访问方式三：通过ServletActionContext对象静态方法获取</h1>
    <form action="${ pageContext.request.contextPath }/requestDemo3.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>
  //action
      public class RequestDemo3Action extends ActionSupport{

      @Override
      public String execute() throws Exception {
        // 接收参数:
        /**
         * ServletActionContext在Struts2的API中的:
         * * HttpServletRequest getRequest();
         * * HttpServletResponse getResponse();
         * * ServletContext getServletContext();
         */
        HttpServletRequest request = ServletActionContext.getRequest();
        Map<String, String[]> parameterMap = request.getParameterMap();
        for (String key : parameterMap.keySet()) {
          String[] value = parameterMap.get(key);
          System.out.println(key+"   "+Arrays.toString(value));
        }
        // 向域中存值：
        request.setAttribute("reqName", "r郝宝强");
        request.getSession().setAttribute("sessName", "s郝喆");
        ServletActionContext.getServletContext().setAttribute("appName", "a郝蓉");
        return super.execute();
      }
    }

  //页面
    <h1>Servlet的API的访问方式二：实现特定接口的方式</h1>
    <form action="${ pageContext.request.contextPath }/requestDemo2.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>
  //action
      public class RequestDemo2Action extends ActionSupport implements ServletRequestAware,ServletContextAware{
      private HttpServletRequest request;
      private ServletContext application;

      @Override
      public String execute() throws Exception {
        // 接收数据：使用request对象。
        Map<String, String[]> parameterMap = request.getParameterMap();
        for (String key : parameterMap.keySet()) {
          String[] arrs = parameterMap.get(key);
          System.out.println(key+"   "+Arrays.toString(arrs));

        }
        // 向域中保存数据；
      //		向request域中保存数据
        request.setAttribute("reqName", "r郝三");
         // 向session域中保存数据
        request.getSession().setAttribute("sessName", "s李四");
        // 向application域中保存数据
        application.setAttribute("appName", "a王五");
        return NONE;
      }

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

      @Override
      public void setServletContext(ServletContext application) {
        this.application = application;
      }
    }