创建MDC上下文
public class MdcContext
{
/** MDC上下文,存储tId */
private static final ThreadLocal<String> CONTEXT = new ThreadLocal();
/**
* 获取tId,放入线程上下文中
* @return
*/
public static String getTraceId()
{
String tId = CONTEXT.get();
if (StringUtils.isEmpty(tId))
{
CONTEXT.set(UUID.randomUUID().toString());
}
return CONTEXT.get();
}
/**
* 清除线程上下文
*/
public static void clear()
{
CONTEXT.remove();
}
}
创建MDC过滤器
利用Spring MVC提供的org.springframework.web.servlet.HandlerInterceptor可以很方便的拦截HTTP请求,对请求处理前后做一些处理:
public class MdcInterceptor implements HandlerInterceptor
{
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception
{
// 获取tId
String tId = MdcContext.getTraceId();
// 将tId放入MDC中,方便日志输出
MDC.put("TraceId", tId);
return true;
}
@Override
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception
{
// 清除线程上下文
MdcContext.clear();
// 清楚MDC内容
MDC.clear();
}
}
并将该拦截器配置上:
@Configuration
public class WebConfig implements WebMvcConfigurer {
@Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(new MdcInterceptor());
}
}
到此,MDC的拦截器就完成了,最后就可以改造一下上面的FeignRequestInterceptor:这个类里面不再生成tId,而是直接从线程上下文中获得:
import com.tw.tsm.base.MdcContext;
import feign.RequestInterceptor;
import feign.RequestTemplate;
import lombok.extern.slf4j.Slf4j;
@Slf4j
public class FeignRequestInterceptor implements RequestInterceptor
{
/**
* Called for every request. Add data using methods on the supplied {@link RequestTemplate}.
*
* @param template
*/
@Override
public void apply(RequestTemplate template)
{
String tId = "tId" + MdcContext.getTraceId();
log.info("----------------传递tId:{}", tId);
template.header("tId", tId);
}
}
最后就是在logback配置文件中,设置tId的打印格式:
<appender name="stdout" class="ch.qos.logback.core.ConsoleAppender">
<!--定义了一个过滤器,在LEVEL之下的日志输出不会被打印出来-->
<!--这里定义了DEBUG,也就是控制台不会输出比ERROR级别小的日志-->
<filter class="ch.qos.logback.classic.filter.ThresholdFilter">
<level>INFO</level>
</filter>
<!-- encoder 默认配置为PatternLayoutEncoder -->
<!--定义控制台输出格式-->
<encoder>
<pattern>%d [%thread] [%X{TraceId}] %-5level %logger{36} [%file : %line] - %msg%n</pattern>
</encoder>
</appender>