Spring Boot微服务中Log4j2集成请求头追踪ID的最佳实践

import org.apache.logging.log4j.ThreadContext;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestHeader;
import org.springframework.web.bind.annotation.RestController;
import lombok.extern.slf4j.Slf4j; // 使用Lombok简化日志声明

@RestController
@Slf4j // Lombok注解，自动生成log静态字段
public class MyController {

    private final MyService myService; // 假设有一个服务层

    public MyController(MyService myService) {
        this.myService = myService;
    }

    @GetMapping("/api/data")
    public ResponseEntity<String> getData(@RequestHeader(value = "track_number", required = false) String trackNumber) {
        String trackingId = trackNumber != null ? trackNumber : generateUniqueId(); // 如果没有提供，生成一个

        // 将追踪ID存入ThreadContext，键名为"TID"
        ThreadContext.put("TID", trackingId);
        log.info("Request received with Tracking ID: {}", trackingId);

        try {
            // 调用服务层逻辑，服务层及其后续调用中产生的日志都将包含TID
            String result = myService.processData();
            log.info("Processing complete for Tracking ID: {}", trackingId);
            return ResponseEntity.ok("Data processed: " + result);
        } finally {
            // 在响应返回之前，务必清除ThreadContext，防止线程池复用导致数据混乱
            ThreadContext.clearAll(); // 或者 ThreadContext.remove("TID");
        }
    }

    private String generateUniqueId() {
        // 实际应用中可以使用UUID或其他分布式ID生成器
        return "GEN-" + System.currentTimeMillis();
    }
}

<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="WARN">
    <Properties>
        <!-- 定义日志输出模式，其中 %X{TID} 用于查找ThreadContext中的TID -->
        <Property name="LOG_PATTERN">
           %d{yyyy-MM-dd HH:mm:ss.SSS} %-5p %c{10}:%L TrackID: %X{TID} - %m%n
        </Property>
    </Properties>

    <Appenders>
        <Console name="Console" target="SYSTEM_OUT">
            <PatternLayout pattern="${LOG_PATTERN}"/>
        </Console>
        <!-- 也可以配置File或RollingFile Appender -->
        <!-- <File name="File" fileName="logs/application.log">
            <PatternLayout pattern="${LOG_PATTERN}"/>
        </File> -->
    </Appenders>

    <Loggers>
        <Root level="info">
            <AppenderRef ref="Console"/>
            <!-- <AppenderRef ref="File"/> -->
        </Root>
    </Loggers>
</Configuration>

2023-10-27 10:30:00.123 INFO  c.e.MyController:29 TrackID: abc-12345 - Request received with Tracking ID: abc-12345
2023-10-27 10:30:00.125 INFO  c.e.MyService:15 TrackID: abc-12345 - Processing data in service layer.
2023-10-27 10:30:00.128 INFO  c.e.MyController:33 TrackID: abc-12345 - Processing complete for Tracking ID: abc-12345