點擊關(guān)注公眾號，Java干貨及時送達

牛逼！又發(fā)現(xiàn)了一款面試題庫，太全了??！
（點擊查看）

最近項目進入聯(lián)調(diào)階段，服務層的接口需要和協(xié)議層進行交互，協(xié)議層需要將入?yún)json字符串]組裝成服務層所需的json字符串，組裝的過程中很容易出錯。入?yún)⒊鲥e導致接口調(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∫幌拢瑫r協(xié)議層調(diào)用服務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)?/p>

@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)?、結(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)?br>?????*?@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;
}
復制代碼


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)?br>?????*?@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)。