寫了個牛逼的日志切面，甩鍋更方便了！

入?yún)⒊鲥e導(dǎo)致接口調(diào)試失敗問題在聯(lián)調(diào)中出現(xiàn)很多次，因此就想寫一個請求日志切面把入?yún)⑿畔⒋蛴∫幌?，同時協(xié)議層調(diào)用服務(wù)層接口名稱對不上也出現(xiàn)了幾次，通過請求日志切面就可以知道上層是否有沒有發(fā)起調(diào)用，方便前后端甩鍋還能拿出證據(jù)。

寫在前面

本篇文章是實戰(zhàn)性的，對于切面的原理不會講解，只會簡單介紹一下切面的知識點

切面介紹

面向切面編程是一種編程范式，它作為 OOP 面向?qū)ο缶幊痰囊环N補充，用于處理系統(tǒng)中分布于各個模塊的橫切關(guān)注點，比如事務(wù)管理、權(quán)限控制、緩存控制、日志打印等等。

AOP 把軟件的功能模塊分為兩個部分：核心關(guān)注點和橫切關(guān)注點。業(yè)務(wù)處理的主要功能為核心關(guān)注點，而非核心、需要拓展的功能為橫切關(guān)注點。AOP 的作用在于分離系統(tǒng)中的各種關(guān)注點，將核心關(guān)注點和橫切關(guān)注點進行分離，使用切面有以下好處：

• 集中處理某一關(guān)注點 / 橫切邏輯

• 可以很方便的添加 / 刪除關(guān)注點

• 侵入性少，增強代碼可讀性及可維護性 因此當(dāng)想打印請求日志時很容易想到切面，對控制層代碼 0 侵入

切面的使用【基于注解】

• @Aspect => 聲明該類為一個注解類

切點注解：

• @Pointcut => 定義一個切點，可以簡化代碼

通知注解：

• @Before => 在切點之前執(zhí)行代碼

• @After => 在切點之后執(zhí)行代碼

• @AfterReturning => 切點返回內(nèi)容后執(zhí)行代碼，可以對切點的返回值進行封裝

• @AfterThrowing => 切點拋出異常后執(zhí)行

• @Around => 環(huán)繞，在切點前后執(zhí)行代碼

動手寫一個請求日志切面

• 使用 @Pointcut 定義切點

@Pointcut("execution(*?your_package.controller..*(..))")??
public?void?requestServer()?{??
}??
?

@Pointcut 定義了一個切點，因為是請求日志切邊，因此切點定義的是 Controller 包下的所有類下的方法。定義切點以后在通知注解中直接使用 requestServer 方法名就可以了

• 使用 @Before 再切點前執(zhí)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());??
}??
?

在進入 Controller 方法前，打印出調(diào)用方 IP、請求 URL、HTTP 請求類型、調(diào)用的方法名

• 使用 @Around 打印進入控制層的入?yún)?/section>

@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?yún)ⅰ⒔Y(jié)果以及耗時

• getRquestParams 方法

private?Map?getRequestParams(ProceedingJoinPoint?proceedingJoinPoint)?{??
??Map?requestParams?=?new?HashMap<>();??
??
???//參數(shù)名??
??String[]?paramNames?=?((MethodSignature)proceedingJoinPoint.getSignature()).getParameterNames();??
??//參數(shù)值??
??Object[]?paramValues?=?proceedingJoinPoint.getArgs();??
??
??for?(int?i?=?0;?i???Object?value?=?paramValues[i];??
??
??//如果是文件對象??
??if?(value?instanceof?MultipartFile)?{??
??MultipartFile?file?=?(MultipartFile)?value;??
??value?=?file.getOriginalFilename();??//獲取文件名??
??}??
??
??requestParams.put(paramNames[i],?value);??
??}??
??
??return?requestParams;??
?}??
?

通過 @PathVariable 以及 @RequestParam 注解傳遞的參數(shù)無法打印出參數(shù)名，因此需要手動拼接一下參數(shù)名，同時對文件對象進行了特殊處理，只需獲取文件名即可

• @After 方法調(diào)用后執(zhí)行

@After("requestServer()")??
public?void?doAfter(JoinPoint?joinPoint)?{??
?LOGGER.info("===============================End========================");??
}??
?

沒有業(yè)務(wù)邏輯只是打印了 End

• 完整切面代碼

@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========================");??
?}??
??
?/**??
??*?獲取入?yún)??
??*?@param?proceedingJoinPoint??
??*??
??*?@return??
??*?*/??
?private?Map?getRequestParams(ProceedingJoinPoint?proceedingJoinPoint)?{??
?Map?requestParams?=?new?HashMap<>();??
??
?//參數(shù)名??
?String[]?paramNames?=??
((MethodSignature)proceedingJoinPoint.getSignature()).getParameterNames();??
?//參數(shù)值??
?Object[]?paramValues?=?proceedingJoinPoint.getArgs();??
??
?for?(int?i?=?0;?i??Object?value?=?paramValues[i];??
??
?//如果是文件對象??
?if?(value?instanceof?MultipartFile)?{??
?MultipartFile?file?=?(MultipartFile)?value;??
?value?=?file.getOriginalFilename();??//獲取文件名??
?}??
??
?requestParams.put(paramNames[i],?value);??
?}??
??
?return?requestParams;??
?}??
}??
?

高并發(fā)下請求日志切面

寫完以后對自己的代碼很滿意，但是想著可能還有完善的地方就和朋友交流了一下。emmmm

果然還有繼續(xù)優(yōu)化的地方 每個信息都打印一行，在高并發(fā)請求下確實會出現(xiàn)請求之間打印日志串行的問題，因為測試階段請求數(shù)量較少沒有出現(xiàn)串行的情況，果然生產(chǎn)環(huán)境才是第一發(fā)展力，能夠遇到更多 bug，寫更健壯的代碼 解決日志串行的問題只要將多行打印信息合并為一行就可以了，因此構(gòu)造一個對象

• 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;??
}??
?

• 環(huán)繞通知方法體

@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;??
}??
?

將 url、http request 這些信息組裝成 RequestInfo 對象，再序列化打印對象
打印序列化對象結(jié)果而不是直接打印對象是因為序列化有更直觀、更清晰，同時可以借助在線解析工具對結(jié)果進行解析

是不是還不錯

在解決高并發(fā)下請求串行問題的同時添加了對異常請求信息的打印，通過使用 @AfterThrowing 注解對拋出異常的方法進行處理

• RequestErrorInfo.java

@Data??
public?class?RequestErrorInfo?{??
?private?String?ip;??
?private?String?url;??
?private?String?httpMethod;??
?private?String?classMethod;??
?private?Object?requestParams;??
?private?RuntimeException?exception;??
}??
?

• 異常通知環(huán)繞體

@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));??
}??
?

對于異常，耗時是沒有意義的，因此不統(tǒng)計耗時，而是添加了異常的打印

最后放一下完整日志請求切面代碼：

@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));??
????}??
??
????/**??
?????*?獲取入?yún)??
?????*?@param?proceedingJoinPoint??
?????*??
?????*?@return??
?????*?*/??
????private?Map?getRequestParamsByProceedingJoinPoint(ProceedingJoinPoint?proceedingJoinPoint)?{??
????????//參數(shù)名??
????????String[]?paramNames?=?((MethodSignature)proceedingJoinPoint.getSignature()).getParameterNames();??
????????//參數(shù)值??
????????Object[]?paramValues?=?proceedingJoinPoint.getArgs();??
??
????????return?buildRequestParam(paramNames,?paramValues);??
????}??
??
????private?Map?getRequestParamsByJoinPoint(JoinPoint?joinPoint)?{??
????????//參數(shù)名??
????????String[]?paramNames?=?((MethodSignature)joinPoint.getSignature()).getParameterNames();??
????????//參數(shù)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?????????????Object?value?=?paramValues[i];??
??
????????????//如果是文件對象??
????????????if?(value?instanceof?MultipartFile)?{??
????????????????MultipartFile?file?=?(MultipartFile)?value;??
????????????????value?=?file.getOriginalFilename();??//獲取文件名??
????????????}??
??
????????????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;??
????}??
}??
?

趕緊給你們的應(yīng)用加上吧【如果沒加的話】，沒有日志的話，總懷疑上層出錯，但是卻拿不出證據(jù)

關(guān)于 traceId 跟蹤定位，可以根據(jù) traceId 跟蹤整條調(diào)用鏈，以 log4j2 為例介紹如何加入 traceId

• 添加攔截器

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);??
?}??
}??
?

在調(diào)用前通過 ThreadContext 加入 traceId，調(diào)用完成后移除

• 修改日志配置文件 在原來的日志格式中
  添加 traceId 的占位符

[TRACEID:%X{traceId}]?%d{HH:mm:ss.SSS}?%-5level?%class{-1}.%M()/%L?-?%msg%xEx%n??
?

• 執(zhí)行效果

日志跟蹤更方便

DMC 是配置 logback 和 log4j 使用的，使用方式和 ThreadContext 差不多，將 ThreadContext.put 替換為 MDC.put 即可，同時修改日志配置文件。

log4j2 也是可以配合 MDC 一起使用的

MDC 是 slf4j 包下的，其具體使用哪個日志框架與我們的依賴有關(guān)。

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