SpringBootMDC全链路调用日志跟踪实现详解

public class LogInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(httpservletRequest request, HttpServletResponse response, Object handler) throws Exception {
        //如果有上层调用就用上层的ID
        String traceId = request.getHeader(Constants.TRACE_ID);
        if (traceId == null) {
            traceId = TraceIdUtil.getTraceId();
        }
        MDC.put(Constants.TRACE_ID, 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 {
        //调用结束后删除
        MDC.remove(Constants.TRACE_ID);
    }
}

<!-- 日志输出格式 -->
<property name="log.pattern" value="[TraceId:%X{traceId}] %d{HH??ss.SSS} [%thread] %-5level %logger{20} - [%method,%line] - %msg%n"/>

   //获取traceId
   Map<String, String> mdcContextMap = MDC.getCopyOfContextMap();
   return  () ->{
     //添加到子线程中
     MDC.setContextMap(mdcContextMap);
     System.out.println("你好呀！");
   }