/*** 检查用户是否已经完成登录*/
@WebFilter(filterName = "loginCheckFilter",urlPatterns = "/*")
@Slf4j
public class LoginCheckFilter implements Filter{//路径匹配器，支持通配符public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();@Overridepublic void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {HttpServletRequest request = (HttpServletRequest) servletRequest;HttpServletResponse response = (HttpServletResponse) servletResponse;//1、获取本次请求的URIString requestURI = request.getRequestURI();// /backend/index.htmllog.info("拦截到请求：{}",requestURI);//定义不需要处理的请求路径String[] urls = new String[]{"/employee/login","/employee/logout","/backend/**","/front/**","/common/**","/user/sendMsg","/user/login","/doc.html","/webjars/**","/swagger-resources","/v2/api-docs"};//2、判断本次请求是否需要处理boolean check = check(urls, requestURI);//3、如果不需要处理，则直接放行if(check){log.info("本次请求{}不需要处理",requestURI);filterChain.doFilter(request,response);return;}//4-1、判断登录状态，如果已登录，则直接放行if(request.getSession().getAttribute("employee") != null){log.info("用户已登录，用户id为：{}",request.getSession().getAttribute("employee"));Long empId = (Long) request.getSession().getAttribute("employee");BaseContext.setCurrentId(empId);filterChain.doFilter(request,response);return;}//4-2、判断登录状态，如果已登录，则直接放行if(request.getSession().getAttribute("user") != null){log.info("用户已登录，用户id为：{}",request.getSession().getAttribute("user"));Long userId = (Long) request.getSession().getAttribute("user");BaseContext.setCurrentId(userId);filterChain.doFilter(request,response);return;}log.info("用户未登录");//5、如果未登录则返回未登录结果，通过输出流方式向客户端页面响应数据response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));return;}/*** 路径匹配，检查本次请求是否需要放行* @param urls* @param requestURI* @return*/public boolean check(String[] urls,String requestURI){for (String url : urls) {boolean match = PATH_MATCHER.match(url, requestURI);if(match){return true;}}return false;}
}

需要在引导类上, 加上Servlet组件扫描的注解, 来扫描过滤器配置的@WebFilter注解， 扫描上之后， 过滤器在运行时就生效了。

@Slf4j
@SpringBootApplication
@ServletComponentScan
public class ReggieApplication {public static void main(String[] args) {SpringApplication.run(ReggieApplication.class,args);log.info("项目启动成功...");}
}