Question

我需要在后台使用JavaScript定期创建HTTP服务。

每次通话都不得影响会话超时（会话时钟功能）。

有可能吗？应该如何以可靠的方式完成？

Answer 1

好的，我是在Filter的帮助下完成的。会话到期截止日期存储在会话中并由http请求更新。具有无状态参数的用户不会更新到期超时。这是我的代码：

public class SessionTimeoutFilter implements Filter {

private static final Logger log = LoggerFactory.getLogger(SessionTimeoutFilter.class);

/** The http stateless request parameter name. */
private final static String PAR_HTTP_STATELESS_REQUEST = "stateless";

/** The session expiry time argument name. */
private final static String ARG_SESSION_EXPIRY_TIME = "sessionExpiryTime";

@Override
public void init(FilterConfig filterConfig) throws ServletException {}

@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain filterChain) throws IOException, ServletException {
    try {
        HttpServletRequest httpReq = (HttpServletRequest) request;

        if (httpReq.getParameterMap().containsKey(PAR_HTTP_STATELESS_REQUEST)) {
            // do nothing
        } else {
            HttpSession session = httpReq.getSession(false);
            if (session != null) {
                Object expirationTime = session.getAttribute(ARG_SESSION_EXPIRY_TIME);

                if (expirationTime != null && expirationTime instanceof Long) {
                    Long expirationDate = (Long) expirationTime;

                    if (expirationDate < System.currentTimeMillis()) {
                        // manual expiration
                        session.invalidate();
                        session = null;
                    }
                } 

                // session still active
                if (session != null) {
                    long currTime = System.currentTimeMillis();
                    long expiryTime = currTime + session.getMaxInactiveInterval() * 1000;

                    // new expiration deadline
                    session.setAttribute(ARG_SESSION_EXPIRY_TIME, new Long(expiryTime));
                }
            }
        }
    } catch (Exception e) {
        log.error("Unable set session timeout cookies due to: " + e, e);
    }

    filterChain.doFilter(request, response);
}

@Override
public void destroy() {}

}

Backgrond服务不会影响http会话超时

1 个答案: