package filter; import javax.servlet.*; import javax.servlet.annotation.WebFilter; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; @WebFilter(filterName = "OnlineCheck",urlPatterns = "/home/*") public class OnlineCheck implements Filter { public void destroy() { } public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws ServletException, IOException { HttpServletRequest request = (HttpServletRequest) req; if(request.getSession().getAttribute("user")==null){ HttpServletResponse response = (HttpServletResponse) resp; response.sendRedirect("/login.jsp"); return; } chain.doFilter(req, resp); } public void init(FilterConfig config) throws ServletException { } }