项目场景：
??有时候一个业务调用链场景，很长，调了各种各样的方法，看日志的时候，各个接口的日志穿插，确实让人头大。为了解决这个痛点，就使用了TraceId，根据TraceId关键字进入服务器查询日志中是否有这个TraceId，这样就把同一次的业务调用链上的日志串起来了。
实现步骤
1、pom.xml 依赖
<dependencies>
????<dependency>
????????<groupId>org.springframework.boot</groupId>
????????<artifactId>spring-boot-starter-web</artifactId>
????</dependency>
????<dependency>
????????<groupId>org.springframework.boot</groupId>
????????<artifactId>spring-boot-starter-test</artifactId>
????????<scope>test</scope>
????</dependency>
????<dependency>
????????<groupId>org.springframework.boot</groupId>
????????<artifactId>spring-boot-starter-logging</artifactId>
????</dependency>
????<!--lombok配置-->
????<dependency>
????????<groupId>org.projectlombok</groupId>
????????<artifactId>lombok</artifactId>
????????<version>1.16.10</version>
????</dependency>
</dependencies>
2、整合logback，打印日志，logback-spring.xml (简单配置下)
关键代码：[traceId:%X{traceId}]，traceId是通过拦截器里MDC.put(traceId, tid)添加
<?xml version="1.0" encoding="UTF-8"?>
<configuration debug="false"><!--日志存储路径--><property name="log" value="D:/test/log" /><!-- 控制台输出 --><appender name="console" class="ch.qos.logback.core.ConsoleAppender"><encoder class="ch.qos.logback.classic.encoder.PatternLayoutEncoder"><!--输出格式化--><pattern>[traceId:%X{traceId}] %d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{50} - %msg%n</pattern></encoder></appender><!-- 按天生成日志文件 --><appender name="file" class="ch.qos.logback.core.rolling.RollingFileAppender"><rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy"><!--日志文件名--><FileNamePattern>${log}/%d{yyyy-MM-dd}.log</FileNamePattern><!--保留天数--><MaxHistory>30</MaxHistory></rollingPolicy><encoder class="ch.qos.logback.classic.encoder.PatternLayoutEncoder"><pattern>[traceId:%X{traceId}] %d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{50} - %msg%n</pattern></encoder><!--日志文件最大的大小--><triggeringPolicy class="ch.qos.logback.core.rolling.SizeBasedTriggeringPolicy"><MaxFileSize>10MB</MaxFileSize></triggeringPolicy></appender><!-- 日志输出级别 --><root level="INFO"><appender-ref ref="console" /><appender-ref ref="file" /></root>
</configuration>
3、application.yml
server:port: 8826
logging:config: classpath:logback-spring.xml
4、自定义日志拦截器 LogInterceptor.java
用途：每一次链路，线程维度，添加最终的链路ID traceId。
MDC(Mapped Diagnostic Context)诊断上下文映射，是@Slf4j提供的一个支持动态打印日志信息的工具。
import org.slf4j.MDC;
import org.springframework.lang.Nullable;
import org.springframework.util.StringUtils;
import org.springframework.web.servlet.HandlerInterceptor;import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.UUID;/*** 日志拦截器*/
public class LogInterceptor implements HandlerInterceptor {private static final String traceId = "traceId";@Overridepublic boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) {String tid = UUID.randomUUID().toString().replace("-", "");//可以考虑让客户端传入链路ID，但需保证一定的复杂度唯一性；如果没使用默认UUID自动生成if (!StringUtils.isEmpty(request.getHeader("traceId"))){tid=request.getHeader("traceId");}MDC.put(traceId, tid);return true;}@Overridepublic void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler,@Nullable Exception ex) {// 请求处理完成后,清除MDC中的traceId,以免造成内存泄漏MDC.remove(traceId);}}
5、WebConfigurerAdapter.java 添加拦截器
ps: 其实这个拦截的部分改为使用自定义注解+aop也是很灵活的。
import javax.annotation.Resource;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport;@Configuration
public class WebConfigurerAdapter extends WebMvcConfigurationSupport {@Resourceprivate LogInterceptor logInterceptor;@Overridepublic void addInterceptors(InterceptorRegistry registry) {registry.addInterceptor(logInterceptor);//可以具体制定哪些需要拦截，哪些不拦截，其实也可以使用自定义注解更灵活完成
// .addPathPatterns("/**")
// .excludePathPatterns("/testxx.html");}
}
6、测试接口
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;import javax.annotation.Resource;@RestController
@Api(tags = "测试接口")
@RequestMapping("/test")
@Slf4j
public class TestController {@RequestMapping(value = "/log", method = RequestMethod.GET)@ApiOperation(value = "测试日志")public String sign() {log.info("这是一行info日志");log.error("这是一行error日志");return "success";}
}
结果：
异步场景：
使用线程的场景，写一个异步线程，加入这个调用里面。再次执行看开效果，我们会发现显然子线程丢失了trackId。
所以我们需要针对子线程使用情形，做调整，思路：将父线程的trackId传递下去给子线程即可。
1、ThreadMdcUtil.java
import org.slf4j.MDC;import java.util.Map;
import java.util.UUID;
import java.util.concurrent.Callable;/*** @Author: JCccc* @Date: 2022-5-30 11:14* @Description:*/
public final class ThreadMdcUtil {private static final String traceId = "traceId";// 获取唯一性标识public static String generateTraceId() {return UUID.randomUUID().toString().replace("-", "");}public static void setTraceIdIfAbsent() {if (MDC.get(traceId) == null) {MDC.put(traceId, generateTraceId());}}/*** 用于父线程向线程池中提交任务时，将自身MDC中的数据复制给子线程** @param callable* @param context* @param <T>* @return*/public static <T> Callable<T> wrap(final Callable<T> callable, final Map<String, String> context) {return () -> {if (context == null) {MDC.clear();} else {MDC.setContextMap(context);}setTraceIdIfAbsent();try {return callable.call();} finally {MDC.clear();}};}/*** 用于父线程向线程池中提交任务时，将自身MDC中的数据复制给子线程** @param runnable* @param context* @return*/public static Runnable wrap(final Runnable runnable, final Map<String, String> context) {return () -> {if (context == null) {MDC.clear();} else {MDC.setContextMap(context);}setTraceIdIfAbsent();try {runnable.run();} finally {MDC.clear();}};}
}
2、MyThreadPoolTaskExecutor.java 是我们自己写的，重写了一些方法
import org.slf4j.MDC;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;import java.util.concurrent.Callable;
import java.util.concurrent.Future;public final class MyThreadPoolTaskExecutor extends ThreadPoolTaskExecutor {public MyThreadPoolTaskExecutor() {super();}@Overridepublic void execute(Runnable task) {super.execute(ThreadMdcUtil.wrap(task, MDC.getCopyOfContextMap()));}@Overridepublic <T> Future<T> submit(Callable<T> task) {return super.submit(ThreadMdcUtil.wrap(task, MDC.getCopyOfContextMap()));}@Overridepublic Future<?> submit(Runnable task) {return super.submit(ThreadMdcUtil.wrap(task, MDC.getCopyOfContextMap()));}
}
3、ThreadPoolConfig.java 定义线程池，交给spring管理
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.annotation.EnableAsync;import java.util.concurrent.Executor;@EnableAsync
@Configuration
public class ThreadPoolConfig {/*** 声明一个线程池*/@Bean("taskExecutor")public Executor taskExecutor() {MyThreadPoolTaskExecutor executor = new MyThreadPoolTaskExecutor();//核心线程数5：线程池创建时候初始化的线程数executor.setCorePoolSize(5);//最大线程数5：线程池最大的线程数，只有在缓冲队列满了之后才会申请超过核心线程数的线程executor.setMaxPoolSize(5);//缓冲队列500：用来缓冲执行任务的队列executor.setQueueCapacity(500);//允许线程的空闲时间60秒：当超过了核心线程出之外的线程在空闲时间到达之后会被销毁executor.setKeepAliveSeconds(60);//线程池名的前缀：设置好了之后可以方便我们定位处理任务所在的线程池executor.setThreadNamePrefix("taskExecutor-");executor.initialize();return executor;}
}
4、Service
import lombok.extern.slf4j.Slf4j;
import org.springframework.scheduling.annotation.Async;
import org.springframework.stereotype.Service;/*** 测试Service*/
@Service("testService")
@Slf4j
public class TestService {/*** 异步操作测试*/@Async("taskExecutor")public void asyncTest() {try {log.info("模拟异步开始......");Thread.sleep(3000);log.info("模拟异步结束......");} catch (InterruptedException e) {log.error("异步操作出错:"+e);}}}
5、测试接口
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;import javax.annotation.Resource;@RestController
@Api(tags = "测试接口")
@RequestMapping("/test")
@Slf4j
public class TestController {@Resourceprivate TestService testService;@RequestMapping(value = "/log", method = RequestMethod.GET)@ApiOperation(value = "测试日志")public String sign() {log.info("这是一行info日志");log.error("这是一行error日志");//异步操作测试testService.asyncTest();return "success";}
}
结果：
我们可以看到，子线程的日志也被串起来了。
定时任务：
如果使用了定时任务@Scheduled，这时候执行定时任务，不会走上面的拦截器逻辑，所以定时任务需要单独创建个AOP切面。
1、创建个定时任务线程池
import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.annotation.EnableScheduling;
import org.springframework.scheduling.annotation.SchedulingConfigurer;
import org.springframework.scheduling.config.ScheduledTaskRegistrar;import java.util.concurrent.Executors;/*** 定时任务线程池*/
@EnableScheduling
@Configuration
public class SeheduleConfig implements SchedulingConfigurer{@Overridepublic void configureTasks(ScheduledTaskRegistrar taskRegistrar) {taskRegistrar.setScheduler(Executors.newScheduledThreadPool(5));}
}
2、创建个AOP切面
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Pointcut;
import org.slf4j.MDC;
import org.springframework.context.annotation.Configuration;import java.util.UUID;@Aspect //定义一个切面
@Configuration
public class SeheduleTaskAspect {// 定义定时任务切点Pointcut@Pointcut("@annotation(org.springframework.scheduling.annotation.Scheduled)")public void seheduleTask() {}@Around("seheduleTask()")public void doAround(ProceedingJoinPoint joinPoint) throws Throwable {try {String traceId = UUID.randomUUID().toString().replace("-", "");//用于日志链路追踪，logback配置:%X{traceId}MDC.put("traceId", traceId);//执行定时任务方法joinPoint.proceed();} finally {//请求处理完成后，清除MDC中的traceId，以免造成内存泄漏MDC.remove("traceId");}}}
3、创建定时任务测试
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Service;import java.util.Date;@Service
public class SeheduleTasks {private Logger logger = LoggerFactory.getLogger(SeheduleTasks.class);/*** 1分钟执行一次*/@Scheduled(cron = "0 0/1 * * * ?")public void testTask() {logger.info("执行定时任务>"+new Date());}}
总结：
服务启动的时候traceId是空的，这是正常的，因为还没到拦截器这一层。
源码：https://download.csdn.net/download/u011974797/89981672
API 说明
clear()=> 移除所有 MDCget (String key)=> 获取当前线程 MDC 中指定 key 的值getContext()=> 获取当前线程 MDC 的 MDCput(String key, Object o)=> 往当前线程的 MDC 中存入指定的键值对remove(String key)=> 删除当前线程 MDC 中指定的键值对
