SpringBoot 统计API接口用时该使用过滤器还是拦截器?

** 统计请求的处理时间（用时）既可以使用

Servlet 过滤器（Filter）

，也可以使用

Spring 拦截器（Interceptor）

。两者都可以在请求处理前后插入自定义逻辑，从而实现对请求响应时间的统计。**

使用建议

** 如果你需要在更底层、与框架无关的地方记录所有请求（包括静态资源请求）的处理时间，那么

Servlet 过滤器

是一个更好的选择。**

** 如果你正在使用 Spring MVC 并且关注的是 Controller 层的处理时间，或者需要访问到 Spring 上下文中的服务，那么

Spring 拦截器

可能更为合适。**

代码样例

** Servlet 过滤器（Filter）**

importjakarta.servlet.*;importjakarta.servlet.http.HttpServletRequest;importjakarta.servlet.http.HttpServletResponse;importlombok.extern.slf4j.Slf4j;importorg.springframework.stereotype.Component;importjava.io.IOException;importjava.time.Instant;// @Component 注册时会new 这里无需指定 registration.setFilter(new LogFilter());@Slf4jpublicclassLogFilterimplementsFilter{@OverridepublicvoiddoFilter(ServletRequest request,ServletResponse response,FilterChain chain)throwsIOException,ServletException{System.err.println("***LogFilter.doFilter.start***");HttpServletRequest httpReq =(HttpServletRequest) request;long startTime =Instant.now().toEpochMilli();// 记录请求开始时间及请求信息
        log.warn("LogFilter.doFilter: Start processing request at {} - {}",Instant.now(), httpReq.getRequestURI());try{// 将请求传递给下一个过滤器或目标资源
            chain.doFilter(request, response);}finally{// 记录请求结束时间及响应状态码long endTime =Instant.now().toEpochMilli();int statusCode =((HttpServletResponse) response).getStatus();
            log.warn("LogFilter.doFilter: Finished processing request at {} - {} in {} ms. Status code: {}",Instant.now(), httpReq.getRequestURI(),(endTime - startTime), statusCode);}System.err.println("***LogFilter.doFilter.end***");}}

** 注册过滤器（Filter）**

@ConfigurationpublicclassAppConfig{@BeanpublicFilterRegistrationBean<LogFilter>tokenFilterRegistration(){FilterRegistrationBean<LogFilter> registration =newFilterRegistrationBean<>();
        registration.setFilter(newLogFilter());// 可以设置过滤器名称
        registration.setName("logFilter");// 设置拦截规则
        registration.addUrlPatterns("/*");// 拦截所有请求// 设置过滤器执行顺序，默认为0，数值越小优先级越高
        registration.setOrder(1);return registration;}}

** Spring 拦截器（Interceptor）**

importjakarta.servlet.http.HttpServletRequest;importjakarta.servlet.http.HttpServletResponse;importlombok.extern.slf4j.Slf4j;importorg.springframework.stereotype.Component;importorg.springframework.web.servlet.HandlerInterceptor;importorg.springframework.web.servlet.ModelAndView;importjava.time.Instant;@Component@Slf4jpublicclassLogInterceptorimplementsHandlerInterceptor{@OverridepublicbooleanpreHandle(HttpServletRequest request,HttpServletResponse response,Object handler){System.err.println("***LogInterceptor.preHandle***");long startTime =Instant.now().toEpochMilli();
        request.setAttribute("startTime", startTime);
        log.warn("LogInterceptor.postHandle: Start processing request at {} - {}",Instant.now(), request.getRequestURI());returntrue;}@OverridepublicvoidpostHandle(HttpServletRequest request,HttpServletResponse response,Object handler,ModelAndView modelAndView){System.err.println("***LogInterceptor.preHandle***");// 获取请求开始时间Long startTime =(Long) request.getAttribute("startTime");if(startTime !=null){long executionTime =Instant.now().toEpochMilli()- startTime;int statusCode = response.getStatus();
            log.warn("LogInterceptor.postHandle: Finished processing request at {} - {} in {} ms. Status code: {}",Instant.now(), request.getRequestURI(), executionTime, statusCode);}}@OverridepublicvoidafterCompletion(HttpServletRequest request,HttpServletResponse response,Object handler,Exception ex)throwsException{System.err.println("***LogInterceptor.afterCompletion***");// 在此可以添加额外的后处理逻辑，但本例中我们不需要}}

** 注册拦截器（Interceptor）**

@ConfigurationpublicclassWebMvcConfigimplementsWebMvcConfigurer{@AutowiredprivateResponsePostInterceptor responsePostInterceptor;@AutowiredprivateLogInterceptor logInterceptor;/**
     * 为拦截器注册表添加拦截器
     *
     * @param registry 拦截器注册表
     */@OverridepublicvoidaddInterceptors(InterceptorRegistry registry){// 在Spring MVC配置中注册一个名为responsePostInterceptor的拦截器，使其能够对匹配路径“/**”（即对应用程序中的所有路径）的请求进行拦截
        registry.addInterceptor(responsePostInterceptor).addPathPatterns("/**");
        registry.addInterceptor(logInterceptor).addPathPatterns("/**");}}

**[Ref]**在Spring Boot中注册过滤器几种方式

测试验证

# 过滤器开始计时***LogFilter.doFilter.start***[2024-01-1708:17:55][WARN][http-nio-8080-exec-2][LogFilter.java:22] → [LogFilter.doFilter: Start processing request at 2024-01-17T00:17:55.662652400Z -/students]***RequestHeaderCheckFilter.doFilter.start***# 拦截器组的 preHandle***ResponsePostInterceptor.preHandle***# log用时拦截器开始计时***LogInterceptor.preHandle***[2024-01-1708:17:55][WARN][http-nio-8080-exec-2][LogInterceptor.java:20] → [LogInterceptor.postHandle: Start processing request at 2024-01-17T00:17:55.852229500Z -/students]# Controller层***StudentController.edit***[2024-01-1708:17:56][INFO][http-nio-8080-exec-2][HikariDataSource.java:110] → [practisedb - Starting...][2024-01-1708:17:56][INFO][http-nio-8080-exec-2][HikariPool.java:565] → [practisedb - Added connection com.mysql.cj.jdbc.ConnectionImpl@34a6ebfc][2024-01-1708:17:56][INFO][http-nio-8080-exec-2][HikariDataSource.java:123] → [practisedb - Start completed.]# @ControllerAdvice对Response增强，比如修改状态码，补充header值***ResponsePostAdvice.supports******ResponsePostAdvice.beforeBodyWrite***# 拦截器组的 postHandle***LogInterceptor.postHandle***# log用时拦截器结束计时[2024-01-1708:17:56][WARN][http-nio-8080-exec-2][LogInterceptor.java:32] → [LogInterceptor.postHandle: Finished processing request at 2024-01-17T00:17:56.636557900Z -/students in784ms. Status code:200]***ResponsePostInterceptor.postHandle***# 拦截器组的 afterCompletion***LogInterceptor.afterCompletion******ResponsePostInterceptor.afterCompletion***# 过滤器结束计时***RequestHeaderCheckFilter.doFilter.end***[2024-01-1708:17:56][WARN][http-nio-8080-exec-2][LogFilter.java:31] → [LogFilter.doFilter: Finished processing request at 2024-01-17T00:17:56.920165800Z -/students in1258ms. Status code:200]***LogFilter.doFilter.end***