问题描述
我需要将相关ID附加到我收到的每个请求的日志中。
这是我的过滤器。直到我进入runAsync()
之类的异步块之前,它都很好用。
我阅读了有关MDC及其如何使用ThreadLocal的信息,但由于它使用了ForkJoinPool,因此无法理解如何在异步中使用它。
@Component
public class Slf4jFilter extends OncePerRequestFilter {
private static final String CORRELATION_ID_HEADER_NAME = "correlation-id";
private static final String CORRELATION_ID_LOG_VAR_NAME = "correlationId";
@Override
protected void doFilterInternal(HttpServletRequest request,HttpServletResponse response,FilterChain chain)
throws servletexception,IOException {
try {
ofNullable(request.getHeader(CORRELATION_ID_HEADER_NAME)).ifPresent(correlationId -> MDC
.put(CORRELATION_ID_LOG_VAR_NAME,correlationId));
chain.doFilter(request,response);
}finally {
removeCorrelationId();
}
}
protected void removeCorrelationId() {
MDC.remove(CORRELATION_ID_LOG_VAR_NAME);
}
}
logback.xml
<configuration>
<appender name="stdout" class="ch.qos.logback.core.ConsoleAppender">
<encoder class="ch.qos.logback.classic.encoder.PatternLayoutEncoder">
<pattern>%d{dd-MM-yyyy HH:mm:ss.SSS} [%thread %X{correlationId}] %-5level %logger{36} - %msg %n</pattern>
</encoder>
</appender>
<root level="INFO">
<appender-ref ref="stdout" />
</root>
解决方法
这是我最终的解决方案。感谢@ M.Prokhorov
在项目内部创建一个名为MdcRetention
的类。
public final class MdcRetention {
public static Runnable wrap(final Runnable delegate) {
return new MdcRetainingRunnable() {
@Override
protected void runInContext() {
delegate.run();
}
};
}
private static abstract class MdcRetentionSupport {
protected final Map<String,String> originalMdc;
protected MdcRetentionSupport() {
Map<String,String> originalMdc = MDC.getCopyOfContextMap();
this.originalMdc = originalMdc == null ? Collections.emptyMap() : originalMdc;
}
}
public static abstract class MdcRetainingRunnable extends MdcRetentionSupport implements Runnable {
@Override
public final void run() {
Map<String,String> currentMdc = MDC.getCopyOfContextMap();
MDC.setContextMap(originalMdc);
try {
runInContext();
} finally {
MDC.setContextMap(currentMdc);
}
}
abstract protected void runInContext();
}}
然后使用静态方法runAsync()
将您的Runnable包装在MdcRetention.wrap()
内
之前:
runAsync(() -> someMethod());
之后:
runAsync(wrap(() -> someMethod()));