Spring Boot 微服务中实现用户级别动态日志追踪

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-log4j2</artifactId>
</groupId>

import org.apache.logging.log4j.ThreadContext;
import org.springframework.stereotype.Component;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

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

@Component
public class UserContextInterceptor implements HandlerInterceptor {

    public static final String USER_ID_KEY = "userId";

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        // 假设用户ID从请求头或会话中获取
        // 实际场景中，您可能从JWT token、OAuth2 token或Session中提取用户ID
        String userId = request.getHeader("X-User-ID"); // 示例：从请求头获取

        if (userId != null && !userId.isEmpty()) {
            ThreadContext.put(USER_ID_KEY, userId);
        } else {
            // 如果没有用户ID，可以放入一个默认值或标识
            ThreadContext.put(USER_ID_KEY, "anonymous");
        }
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        // 在请求处理完成后，可以进行一些清理，但通常MDC会在afterCompletion中清理
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        // 请求完成后务必清理MDC，防止内存泄漏或线程上下文污染
        ThreadContext.remove(USER_ID_KEY);
    }
}

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

@Configuration
public class WebConfig implements WebMvcConfigurer {

    private final UserContextInterceptor userContextInterceptor;

    @Autowired
    public WebConfig(UserContextInterceptor userContextInterceptor) {
        this.userContextInterceptor = userContextInterceptor;
    }

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(userContextInterceptor).addPathPatterns("/**");
    }
}

<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="WARN" monitorInterval="5">
    <Appenders>
        <Console name="Console" target="SYSTEM_OUT">
            <PatternLayout pattern="%d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %-5level %logger{36} - %X{userId} - %msg%n"/>
        </Console>
    </Appenders>

    <Loggers>
        <Root level="info">
            <AppenderRef ref="Console"/>
        </Root>

        <!-- 配置 MutableThreadContextMapFilter -->
        <Logger name="com.example.yourservice" level="debug" additivity="false">
            <AppenderRef ref="Console">
                <!-- 引用动态用户过滤规则 -->
                <MutableThreadContextMapFilter configFile="classpath:log4j2-user-filters.json"
                                            pollInterval="30"
                                            onMatch="ACCEPT"
                                            onMismatch="DENY" />
            </AppenderRef>
        </Logger>

    </Loggers>
</Configuration>

{
  "filters": [
    {
      "type": "ThreadContextMapFilter",
      "properties": [
        { "key": "userId", "value": "user123", "operator": "equals", "onMatch": "ACCEPT" },
        { "key": "userId", "value": "user456", "operator": "equals", "onMatch": "ACCEPT" }
      ],
      "onMismatch": "DENY"
    }
  ],
  "levelOverrides": [
    { "logger": "com.example.yourservice", "level": "DEBUG", "condition": { "key": "userId", "value": "user123", "operator": "equals" } },
    { "logger": "com.example.yourservice", "level": "TRACE", "condition": { "key": "userId", "value": "user456", "operator": "equals" } }
  ]
}