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用好Spring AOP，天降大锅从容应对

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bang V管理员 /131阅读/0评论
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用好Spring AOP，天降大锅从容应对

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
  • 可以很方便地添加/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在切点前执行
@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<String, Object> getRequestParams(ProceedingJoinPoint proceedingJoinPoint) {         Map<String, Object> 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<String, Object> getRequestParams(ProceedingJoinPoint proceedingJoinPoint) {          Map<String, Object> 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

用好Spring AOP，天降大锅从容应对

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

用好Spring AOP，天降大锅从容应对

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@Aspectpublic 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<String, Object> 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<String, Object> 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<String, Object> buildRequestParam(String[] paramNames, Object[] paramValues) {        Map<String, Object> 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

用好Spring AOP，天降大锅从容应对

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
<property name="pattern">[TRACEID:%X{traceId}] %d{HH:mm:ss.SSS} %-5level %class{-1}.%M()/%L - %msg%xEx%n</property>
  • 执行效果
用好Spring AOP，天降大锅从容应对

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。

作者 | 何甜甜在吗

来源 | https://juejin.cn/post/6844904087964614670

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