获取HttpServletRequest/HttpSession/ServletContext/HttpServletResponse对象

方法一、通过ServletActionContext类直接获取：

public String rsa() throws Exception{
    HttpServletRequest request = ServletActionContext.getRequest();
    ServletContext servletContext = 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 ServletContext servletContext;
    private HttpServletResponse response;
    public void setServletRequest(HttpServletRequest req) {
        this.request=req;
    }
    public void setServletResponse(HttpServletResponse res) {
        this.response=res;
    }
    public void setServletContext(ServletContext ser) {
        this.servletContext=ser;
    }
}