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摘要: 原创出处 juejin.im/post/6844904087964614670 「何甜甜在吗」欢迎转载,保留摘要,谢谢!


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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<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

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<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

==================== 以下内容更新于2019/3/14 ============== 关于traceId 跟踪定位【地藏Kelvin的评论】,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

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。 推荐使用log4j2,为什么推荐使用log4j2可以看下这篇文章:日志框架,选择Logback Or Log4j2?

==================== 以下内容更新于2019/3/16 ============== 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

文章目录
  1. 1. 写在前面
  2. 2. 切面介绍
  3. 3. 切面的使用【基于注解】
  4. 4. 动手写一个请求日志切面
  5. 5. 高并发下请求日志切面