SpringBoot中的拦截器

SpringBoot中的拦截器

Filter

典型场景 全局鉴权/接口耗时统计

@WebFilter("/*") 
public class CostFilter implements Filter {@Overridepublic void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) {long start = System.currentTimeMillis();chain.doFilter(req, res); // 放行江湖令箭System.out.println("接口耗时："+(System.currentTimeMillis()-start)+"ms");}
}

HandlerInterceptor

典型场景 接口权限验证/请求参数自动装填

public class AuthInterceptor implements HandlerInterceptor {@Overridepublic boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) {String token = request.getHeader("X-Token");if(!"vip666".equals(token)){response.setStatus(403);return false; }return true;}
}@Configuration
publicclass WebMvcConfig implements WebMvcConfigurer {@Overridepublic void addInterceptors(InterceptorRegistry registry) {registry.addInterceptor(new AuthInterceptor()).addPathPatterns("/api/**").excludePathPatterns("/api/login");}
}

AOP拦截

典型场景 服务层方法缓存/事务管理

@Aspect
@Component
public class CacheAspect {@Around("@annotation(com.example.anno.Cacheable)")public Object aroundCache(ProceedingJoinPoint jp) {String cacheKey = buildKey(jp);Object cacheVal = redisTemplate.opsForValue().get(cacheKey);if(cacheVal != null) return cacheVal;Object result = jp.proceed();redisTemplate.opsForValue().set(cacheKey, result, 5, TimeUnit.MINUTES);return result;}
}

RestTemplate

典型场景 统一添加请求头/加密请求参数

public class TraceInterceptor implements ClientHttpRequestInterceptor {@Overridepublic ClientHttpResponse intercept(HttpRequest request, byte[] body, ClientHttpRequestExecution execution) {request.getHeaders().add("X-TraceId", UUID.randomUUID().toString());return execution.execute(request, body);}
}// 注册水军
@Bean
public RestTemplate restTemplate() {RestTemplate rt = new RestTemplate();rt.getInterceptors().add(new TraceInterceptor());return rt;
}

Feign拦截器

典型场景 统一签名计算/Header透传

public class FeignAuthInterceptor implements RequestInterceptor {@Overridepublic void apply(RequestTemplate template) {template.header("Authorization", "Bearer " + SecurityContext.getToken());}
}@Configuration
public class FeignConfig {@Beanpublic FeignAuthInterceptor feignAuthInterceptor() {returnnew FeignAuthInterceptor();}
}

WebFilter

典型场景 响应式编程统一编码/跨域处理

@Component
public class CorsWebFilter implements WebFilter {@Overridepublic Mono<Void> filter(ServerWebExchange exchange, WebFilterChain chain) {ServerHttpResponse response = exchange.getResponse();response.getHeaders().add("Access-Control-Allow-Origin", "*");return chain.filter(exchange);}
}

总结

顺序

Filter -> Interceptor -> AOP ，越早拦截越省力（但别在Filter里做业务）

性能

用Arthas监控拦截链路耗时

# 查看HandlerInterceptor耗时
trace *.preHandle '#cost>10'# 诊断AOP切面
watch com.example.aop.*Aspect * '{params,returnObj}' -x 3