Structured logging (JSON) + Logback + MDC

dependencies {
    implementation("net.logstash.logback:logstash-logback-encoder:8.0")
}

    
    

    
    
        
            %d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
        
    

    
        
            requestId
            userId
            traceId
            {"service":"${appName}","profile":"${activeProfile}"}
        
    

    
        /var/log/taskflow/app.log
        
            /var/log/taskflow/app.%d{yyyy-MM-dd}.%i.log.gz
            100MB
            30
            10GB
        
        
            requestId
            userId
        
    

    
        
            
        
    

    
        
            
            
        
    

logging/RequestLoggingFilter.java:

package com.taskflow.logging;

import jakarta.servlet.FilterChain;
import jakarta.servlet.ServletException;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import org.slf4j.MDC;
import org.springframework.lang.NonNull;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.stereotype.Component;
import org.springframework.web.filter.OncePerRequestFilter;

import java.io.IOException;
import java.util.UUID;

@Component
public class RequestLoggingFilter extends OncePerRequestFilter {

    private static final String REQUEST_ID_HEADER = "X-Request-Id";

    @Override
    protected void doFilterInternal(@NonNull HttpServletRequest request,
                                    @NonNull HttpServletResponse response,
                                    @NonNull FilterChain chain) throws ServletException, IOException {
        // Берём X-Request-Id из заголовка (если есть) или генерим
        String requestId = request.getHeader(REQUEST_ID_HEADER);
        if (requestId == null || requestId.isBlank()) {
            requestId = UUID.randomUUID().toString();
        }
        MDC.put("requestId", requestId);
        response.setHeader(REQUEST_ID_HEADER, requestId);

        // UserId из SecurityContext (если есть)
        Authentication auth = SecurityContextHolder.getContext().getAuthentication();
        if (auth != null && auth.isAuthenticated() && !"anonymousUser".equals(auth.getName())) {
            MDC.put("userId", auth.getName());
        }

        try {
            long start = System.currentTimeMillis();
            chain.doFilter(request, response);
            long duration = System.currentTimeMillis() - start;
            MDC.put("durationMs", String.valueOf(duration));
        } finally {
            MDC.clear();
        }
    }
}

@Slf4j  // Lombok, генерирует log
@Service
public class TaskService {
    // ...

    public TaskResponse create(CreateTaskRequest req) {
        log.info("Creating task: title={}", req.title());  // MDC автоматически в каждой строке
        // ...
        log.info("Task created with id={}", saved.getId());
        return mapper.toResponse(saved);
    }
}

@Slf4j — аннотация Lombok. Если не используете Lombok:

private static final Logger log = LoggerFactory.getLogger(TaskService.class);

{
  "@timestamp": "2026-06-29T16:55:00.123Z",
  "level": "INFO",
  "service": "taskflow",
  "profile": "prod",
  "requestId": "f3e1b5a0-1234-5678-9abc-def012345678",
  "userId": "alice",
  "durationMs": "45",
  "logger_name": "com.taskflow.service.TaskService",
  "thread_name": "http-nio-8080-exec-1",
  "message": "Creating task: title=Test"
}

    
        
            {"password":"***","secret":"***"}
        
    

Или через MessageConverter для конкретных классов.

# Запускаем в prod
SPRING_PROFILES_ACTIVE=prod ./gradlew bootRun

# Делаем запрос с X-Request-Id
$ curl -H "X-Request-Id: test-123" -H "Authorization: Bearer $TOKEN" \
  http://localhost:8080/api/tasks

# В логах:
{"@timestamp":"...","level":"INFO","requestId":"test-123","userId":"alice","message":"Creating task: title=Test"}
{"@timestamp":"...","level":"INFO","requestId":"test-123","userId":"alice","message":"Task created with id=42"}

Все логи в рамках одного запроса имеют requestId=test-123 — легко найти все записи одного запроса.

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