日志之MDC和异步多线程间传递线程

 基于alibabade TTL实现

import com.alibaba.ttl.TransmittableThreadLocal;
import com.dmyz.hc.sign.common.utils.TraceIdUtils;
import com.google.inject.internal.util.Maps;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.slf4j.MDC;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;
import org.springframework.web.servlet.HandlerInterceptor;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.Map;

/**
 * MVC 自定义拦截器<br/>
 *
 * @author wangy
 * @date 2024-06-24 14:00
 */
public class HttpHandlerInterceptor implements HandlerInterceptor {

    private static final Logger LOGGER = LoggerFactory.getLogger(HttpHandlerInterceptor.class);

    /**
     * 实现 TransmittableThreadLocal 的 initialValue,beforeExecute,afterExecute接口
     */
    static TransmittableThreadLocal<Map<String, String>> ttlMDC = new TransmittableThreadLocal<Map<String, String>>() {
        /**
         * 在多线程数据传递的时候，将数据复制一份给MDC
         */
        @Override
        protected void beforeExecute() {
            final Map<String, String> mdc = get();
            mdc.forEach(MDC::put);
        }

        @Override
        protected void afterExecute() {
            MDC.clear();
        }

        @Override
        protected Map<String, String> initialValue() {
            return Maps.newHashMap();
        }
    };

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) {
        ServletRequestAttributes attributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
        RequestContextHolder.setRequestAttributes(attributes, true);

        String traceId = TraceIdUtils.getTraceId(request);
        MDC.put("tid", traceId);
        ttlMDC.get().put("tid", traceId);
        return true;
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)
            throws Exception {
        try {
            MDC.remove("tid");
            ttlMDC.get().remove("tid");
            ttlMDC.remove();
        } catch (Exception e) {
            LOGGER.error("MDC remove id error", e);
        }
        HandlerInterceptor.super.afterCompletion(request, response, handler, ex);
    }


}