写了个牛逼的日志切面,甩锅更方便了
最近项目进入联调阶段,服务层的接口需要和协议层进行交互,协议层需要将入参 [json 字符串] 组装成服务层所需的 json 字符串,组装的过程中很容易出错。
入参出错导致接口调试失败问题在联调中出现很多次,因此就想写一个请求日志切面把入参信息打印一下,同时协议层调用服务层接口名称对不上也出现了几次,通过请求日志切面就可以知道上层是否有没有发起调用,方便前后端甩锅还能拿出证据。
写在前面
本篇文章是实战性的,对于切面的原理不会讲解,只会简单介绍一下切面的知识点
切面介绍
面向切面编程是一种编程范式,它作为 OOP 面向对象编程的一种补充,用于处理系统中分布于各个模块的横切关注点,比如 事务管理 、 权限控制 、 缓存控制 、 日志打印 等等。
AOP 把软件的功能模块分为两个部分:核心关注点和横切关注点。业务处理的主要功能为核心关注点,而非核心、需要拓展的功能为 横切 关注点。AOP 的作用在于分离系统中的各种关注点,将核心关注点和横切关注点进行分离,使用切面有以下好处: 集中处理某一关注点 / 横切逻辑 可以很方便的添加 / 删除关注点 侵入性少,增强代码可读性及可维护性 因此当想打印请求日志时很容易想到切面,对控制层代码 0 侵入 切面的使用【基于注解】@Aspect => 声明该类为一个注解类
切点注解: @Pointcut => 定义一个切点,可以简化代码
通知注解: @Before => 在切点之前执行代码 @After => 在切点之后执行代码 @AfterReturning => 切点返回内容后执行代码,可以对切点的返回值进行封装 @AfterThrowing => 切点抛出异常后执行 @Around => 环绕,在切点前后执行代码 动手写一个请求日志切面使用 @Pointcut 定义切点@Pointcut("execution(* your_package.controller..*(..))") public void requestServer() { }
@Pointcut 定义了一个切点,因为是请求日志切边,因此切点定义的是 Controller 包下的所有类下的方法。定义切点以后在通知注解中直接使用 requestServer 方法名就可以了 使用 @Before 再切点前执行@Before("requestServer()") public void doBefore(JoinPoint joinPoint) { ServletRequestAttributes attributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes(); HttpServletRequest request = attributes.getRequest(); LOGGER.info("===============================Start========================"); LOGGER.info("IP : {}", request.getRemoteAddr()); LOGGER.info("URL : {}", request.getRequestURL().toString()); LOGGER.info("HTTP Method : {}", request.getMethod()); LOGGER.info("Class Method : {}.{}", joinPoint.getSignature().getDeclaringTypeName(), joinPoint.getSignature().getName()); }
在进入 Controller 方法前,打印出调用方 IP、请求 URL、HTTP 请求类型、调用的方法名 使用 @Around 打印进入控制层的入参@Around("requestServer()") public Object doAround(ProceedingJoinPoint proceedingJoinPoint) throws Throwable { long start = System.currentTimeMillis(); Object result = proceedingJoinPoint.proceed(); LOGGER.info("Request Params : {}", getRequestParams(proceedingJoinPoint)); LOGGER.info("Result : {}", result); LOGGER.info("Time Cost : {} ms", System.currentTimeMillis() - start); return result; }
打印了入参、结果以及耗时 getRquestParams 方法private Map getRequestParams(ProceedingJoinPoint proceedingJoinPoint) { Map requestParams = new HashMap<>(); //参数名 String[] paramNames = ((MethodSignature)proceedingJoinPoint.getSignature()).getParameterNames(); //参数值 Object[] paramValues = proceedingJoinPoint.getArgs(); for (int i = 0; i < paramNames.length; i++) { Object value = paramValues[i]; //如果是文件对象 if (value instanceof MultipartFile) { MultipartFile file = (MultipartFile) value; value = file.getOriginalFilename(); //获取文件名 } requestParams.put(paramNames[i], value); } return requestParams; }
通过 @PathVariable 以及 @RequestParam 注解传递的参数无法打印出参数名,因此需要手动拼接一下参数名,同时对文件对象进行了特殊处理,只需获取文件名即可 @After 方法调用后执行@After("requestServer()") public void doAfter(JoinPoint joinPoint) { LOGGER.info("===============================End========================"); }
没有业务逻辑只是打印了 End 完整切面代码@Component @Aspect public class RequestLogAspect { private final static Logger LOGGER = LoggerFactory.getLogger(RequestLogAspect.class); @Pointcut("execution(* your_package.controller..*(..))") public void requestServer() { } @Before("requestServer()") public void doBefore(JoinPoint joinPoint) { ServletRequestAttributes attributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes(); HttpServletRequest request = attributes.getRequest(); LOGGER.info("===============================Start========================"); LOGGER.info("IP : {}", request.getRemoteAddr()); LOGGER.info("URL : {}", request.getRequestURL().toString()); LOGGER.info("HTTP Method : {}", request.getMethod()); LOGGER.info("Class Method : {}.{}", joinPoint.getSignature().getDeclaringTypeName(), joinPoint.getSignature().getName()); } @Around("requestServer()") public Object doAround(ProceedingJoinPoint proceedingJoinPoint) throws Throwable { long start = System.currentTimeMillis(); Object result = proceedingJoinPoint.proceed(); LOGGER.info("Request Params : {}", getRequestParams(proceedingJoinPoint)); LOGGER.info("Result : {}", result); LOGGER.info("Time Cost : {} ms", System.currentTimeMillis() - start); return result; } @After("requestServer()") public void doAfter(JoinPoint joinPoint) { LOGGER.info("===============================End========================"); } /** * 获取入参 * @param proceedingJoinPoint * * @return * */ private Map getRequestParams(ProceedingJoinPoint proceedingJoinPoint) { Map requestParams = new HashMap<>(); //参数名 String[] paramNames = ((MethodSignature)proceedingJoinPoint.getSignature()).getParameterNames(); //参数值 Object[] paramValues = proceedingJoinPoint.getArgs(); for (int i = 0; i < paramNames.length; i++) { Object value = paramValues[i]; //如果是文件对象 if (value instanceof MultipartFile) { MultipartFile file = (MultipartFile) value; value = file.getOriginalFilename(); //获取文件名 } requestParams.put(paramNames[i], value); } return requestParams; } } 高并发下请求日志切面
写完以后对自己的代码很满意,但是想着可能还有完善的地方就和朋友交流了一下。emmmm
果然还有继续优化的地方 每个信息都打印一行,在高并发请求下确实会出现请求之间打印日志串行的问题,因为测试阶段请求数量较少没有出现串行的情况,果然生产环境才是第一发展力,能够遇到更多 bug,写更健壮的代码 解决日志串行的问题只要将多行打印信息合并为一行就可以了,因此构造一个对象 RequestInfo.java@Data public class RequestInfo { private String ip; private String url; private String httpMethod; private String classMethod; private Object requestParams; private Object result; private Long timeCost; } 环绕通知方法体@Around("requestServer()") public Object doAround(ProceedingJoinPoint proceedingJoinPoint) throws Throwable { long start = System.currentTimeMillis(); ServletRequestAttributes attributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes(); HttpServletRequest request = attributes.getRequest(); Object result = proceedingJoinPoint.proceed(); RequestInfo requestInfo = new RequestInfo(); requestInfo.setIp(request.getRemoteAddr()); requestInfo.setUrl(request.getRequestURL().toString()); requestInfo.setHttpMethod(request.getMethod()); requestInfo.setClassMethod(String.format("%s.%s", proceedingJoinPoint.getSignature().getDeclaringTypeName(), proceedingJoinPoint.getSignature().getName())); requestInfo.setRequestParams(getRequestParamsByProceedingJoinPoint(proceedingJoinPoint)); requestInfo.setResult(result); requestInfo.setTimeCost(System.currentTimeMillis() - start); LOGGER.info("Request Info : {}", JSON.toJSONString(requestInfo)); return result; }
将 url、http request 这些信息组装成 RequestInfo 对象,再序列化打印对象
打印 序列化 对象结果而不是直接打印对象是因为序列化有更直观、更清晰,同时可以借助在线解析工具对结果进行解析
是不是还不错
在解决高并发下请求串行问题的同时添加了对 异常请求信息的打印 ,通过使用 @AfterThrowing 注解对抛出异常的方法进行处理 RequestErrorInfo.java@Data public class RequestErrorInfo { private String ip; private String url; private String httpMethod; private String classMethod; private Object requestParams; private RuntimeException exception; } 异常通知环绕体@AfterThrowing(pointcut = "requestServer()", throwing = "e") public void doAfterThrow(JoinPoint joinPoint, RuntimeException e) { ServletRequestAttributes attributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes(); HttpServletRequest request = attributes.getRequest(); RequestErrorInfo requestErrorInfo = new RequestErrorInfo(); requestErrorInfo.setIp(request.getRemoteAddr()); requestErrorInfo.setUrl(request.getRequestURL().toString()); requestErrorInfo.setHttpMethod(request.getMethod()); requestErrorInfo.setClassMethod(String.format("%s.%s", joinPoint.getSignature().getDeclaringTypeName(), joinPoint.getSignature().getName())); requestErrorInfo.setRequestParams(getRequestParamsByJoinPoint(joinPoint)); requestErrorInfo.setException(e); LOGGER.info("Error Request Info : {}", JSON.toJSONString(requestErrorInfo)); }
对于异常,耗时是没有意义的,因此不统计耗时,而是添加了异常的打印
最后放一下完整日志请求切面代码: @Component @Aspect public class RequestLogAspect { private final static Logger LOGGER = LoggerFactory.getLogger(RequestLogAspect.class); @Pointcut("execution(* your_package.controller..*(..))") public void requestServer() { } @Around("requestServer()") public Object doAround(ProceedingJoinPoint proceedingJoinPoint) throws Throwable { long start = System.currentTimeMillis(); ServletRequestAttributes attributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes(); HttpServletRequest request = attributes.getRequest(); Object result = proceedingJoinPoint.proceed(); RequestInfo requestInfo = new RequestInfo(); requestInfo.setIp(request.getRemoteAddr()); requestInfo.setUrl(request.getRequestURL().toString()); requestInfo.setHttpMethod(request.getMethod()); requestInfo.setClassMethod(String.format("%s.%s", proceedingJoinPoint.getSignature().getDeclaringTypeName(), proceedingJoinPoint.getSignature().getName())); requestInfo.setRequestParams(getRequestParamsByProceedingJoinPoint(proceedingJoinPoint)); requestInfo.setResult(result); requestInfo.setTimeCost(System.currentTimeMillis() - start); LOGGER.info("Request Info : {}", JSON.toJSONString(requestInfo)); return result; } @AfterThrowing(pointcut = "requestServer()", throwing = "e") public void doAfterThrow(JoinPoint joinPoint, RuntimeException e) { ServletRequestAttributes attributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes(); HttpServletRequest request = attributes.getRequest(); RequestErrorInfo requestErrorInfo = new RequestErrorInfo(); requestErrorInfo.setIp(request.getRemoteAddr()); requestErrorInfo.setUrl(request.getRequestURL().toString()); requestErrorInfo.setHttpMethod(request.getMethod()); requestErrorInfo.setClassMethod(String.format("%s.%s", joinPoint.getSignature().getDeclaringTypeName(), joinPoint.getSignature().getName())); requestErrorInfo.setRequestParams(getRequestParamsByJoinPoint(joinPoint)); requestErrorInfo.setException(e); LOGGER.info("Error Request Info : {}", JSON.toJSONString(requestErrorInfo)); } /** * 获取入参 * @param proceedingJoinPoint * * @return * */ private Map getRequestParamsByProceedingJoinPoint(ProceedingJoinPoint proceedingJoinPoint) { //参数名 String[] paramNames = ((MethodSignature)proceedingJoinPoint.getSignature()).getParameterNames(); //参数值 Object[] paramValues = proceedingJoinPoint.getArgs(); return buildRequestParam(paramNames, paramValues); } private Map getRequestParamsByJoinPoint(JoinPoint joinPoint) { //参数名 String[] paramNames = ((MethodSignature)joinPoint.getSignature()).getParameterNames(); //参数值 Object[] paramValues = joinPoint.getArgs(); return buildRequestParam(paramNames, paramValues); } private Map buildRequestParam(String[] paramNames, Object[] paramValues) { Map requestParams = new HashMap<>(); for (int i = 0; i < paramNames.length; i++) { Object value = paramValues[i]; //如果是文件对象 if (value instanceof MultipartFile) { MultipartFile file = (MultipartFile) value; value = file.getOriginalFilename(); //获取文件名 } requestParams.put(paramNames[i], value); } return requestParams; } @Data public class RequestInfo { private String ip; private String url; private String httpMethod; private String classMethod; private Object requestParams; private Object result; private Long timeCost; } @Data public class RequestErrorInfo { private String ip; private String url; private String httpMethod; private String classMethod; private Object requestParams; private RuntimeException exception; } }
赶紧给你们的应用加上吧【如果没加的话】,没有日志的话,总怀疑上层出错,但是却拿不出证据
关于 traceId 跟踪定位,可以根据 traceId 跟踪整条调用链,以 log4j2 为例介绍如何加入 traceId 添加拦截器public class LogInterceptor implements HandlerInterceptor { private final static String TRACE_ID = "traceId"; @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { String traceId = java.util.UUID.randomUUID().toString().replaceAll("-", "").toUpperCase(); ThreadContext.put("traceId", traceId); return true; } @Override public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception { } @Override public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception { ThreadContext. remove(TRACE_ID); } }
在调用前通过 ThreadContext 加入 traceId,调用完成后移除 修改日志配置文件 在原来的日志格式中
添加 traceId 的占位符[TRACEID:%X{traceId}] %d{HH:mm:ss.SSS} %-5level %class{-1}.%M()/%L - %msg%xEx%n 执行效果
日志跟踪更方便
DMC 是配置 logback 和 log4j 使用的,使用方式和 ThreadContext 差不多,将 ThreadContext.put 替换为 MDC.put 即可,同时修改日志配置文件。
log4j2 也是可以配合 MDC 一起使用的
MDC 是 slf4j 包下的,其具体使用哪个日志框架与我们的依赖有关。