获取ServletContext

ServletConfig       config.getServletContext()；

GenericServlet      this.getServletContext();

HttpSession         getServletContext()

ServletContextEvent getServletContext()

struts2中

1.ServletActionContext类

public String rsa() throws Exception{

HttpServletRequest request = ServletActionContext.getRequest();

ServletContext servletContext = ServletActionContext.getServletContext();

request.getSession()

HttpServletResponse response = ServletActionContext.getResponse();

return "scope";

}

2. 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;

}

}