写个日志请求切面前后端甩锅更方便

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

写个日志请求切面,前后端甩锅更方便

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

写个日志请求切面,前后端甩锅更方便

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

写个日志请求切面,前后端甩锅更方便
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 >[TRACEID:%X{traceId}] %d{HH:mm:ss.SSS} %-5level %class{-1}.%M()/%L - %msg%xEx%n</property>
  • 执行效果

写个日志请求切面,前后端甩锅更方便

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?

log4j2 也是可以配合 MDC 一起使用的

写个日志请求切面,前后端甩锅更方便

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