访问servletAPI方式

1.通过ActionContext  （推荐）

public class Demo5Action extends ActionSupport {

    public String execute() throws Exception {
        //request域=> map (struts2并不推荐使用原生request域)
        //不推荐
        Map<String, Object> requestScope = (Map<String, Object>) ActionContext.getContext().get("request");
        //推荐
        ActionContext.getContext().put("name", "requestTom");
        //session域 => map
        Map<String, Object> sessionScope = ActionContext.getContext().getSession();
        sessionScope.put("name", "sessionTom");
        //application域=>map
        Map<String, Object> applicationScope = ActionContext.getContext().getApplication();
        applicationScope.put("name", "applicationTom");

        return SUCCESS;
    }
}

2.通过ServletActionContext

public class Demo6Action extends ActionSupport {
    //并不推荐
    public String execute() throws Exception {
        //原生request
        HttpServletRequest request = ServletActionContext.getRequest();
        //原生session
        HttpSession session = request.getSession();
        //原生response
        HttpServletResponse response = ServletActionContext.getResponse();
        //原生servletContext
        ServletContext servletContext = ServletActionContext.getServletContext();
        return SUCCESS;
    }
}

3.通过实现接口方式

public class Demo7Action extends ActionSupport implements ServletRequestAware {

    private HttpServletRequest request;

    public String execute() throws Exception { 

        System.out.println("原生request:"+request);
        return SUCCESS;
    }

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