struts2教程：13、访问或添加request/session/application属性

访问或添加request/session/application属性

struts2避免了直接访问servletAPI，所以没法获取request/session/application对象，但对他们进行了封装。

public String scope() throws Exception{

   ActionContextctx = ActionContext.getContext();

   ctx.getApplication().put("app", "应用范围");//往ServletContext里放入app

   ctx.getSession().put("ses", "session范围");//往session里放入ses

   ctx.put("req", "request范围");//往request里放入req

   return "scope";

}

JSP:

 <body>

    ${applicationScope.app} <br>

    ${sessionScope.ses}<br>

    ${requestScope.req}<br>

 </body>

应用场景：仅仅是为了访问或添加属性用ActionContext

获取HttpServletRequest / HttpSession / ServletContext / HttpServletResponse对象

方法一，通过ServletActionContext.类直接获取：  （建议使用，因为简单）

public String rsa() throws Exception{

  HttpServletRequest request = ServletActionContext.getRequest();

  ServletContextservletContext = ServletActionContext.getServletContext();

  request.getSession()  

  HttpServletResponse response = ServletActionContext.getResponse();

  return "scope";

}

方法二，实现指定接口，由struts框架运行时注入：

public class HelloWorldAction implements ServletRequestAware, ServletResponseAware, ServletContextAware{

  private HttpServletRequest request;

  private ServletContextservletContext;

  private HttpServletResponse response;

  public void setServletRequest(HttpServletRequestreq) {

  this.request=req;

  }

  public void setServletResponse(HttpServletResponse res) {

  this.response=res;

  }

  public void setServletContext(ServletContext ser) {

  this.servletContext=ser;

  }

}

应用场景：比如果要获取站点目录下的真实路径，用ServletActionContext