登陆拦截的几种实现方式

1、过滤器实现拦截登陆

@Component
@WebFilter(filterName = "TestFilter",urlPatterns = "/*")
@Order(1)  //Order(1)在定义多个Filter时，用于决定执行顺序的，数字越小，越先执行。
public class LoginFiilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
    }
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest servletRequest1=(HttpServletRequest) request;
        //放行URL
        if (servletRequest1.getRequestURI().equals("/user/login")){
            filterChain.doFilter(request,response);
        }
        Object user = servletRequest1.getSession().getAttribute("user");
        if (user==null){
            servletRequest1.getRequestDispatcher("/login.jsp").forward(request,response);
        }else {
            //放行请求
            filterChain.doFilter(request,response);
        }
    }
    @Override
    public void destroy() {
    }
}

2、基于Spring Aop实现拦截功能

（1）自定义注解 （2）自定义切面@Aspect并且配置 （3）在需要进行登陆校验的方法上打上自定义注解