Using a TaskDecorator to copy MDC data to @Async threads
阿新 • • 發佈：2019-06-25
在Spring中使用執行緒池執行非同步任務，通過TaskDecorator進行父執行緒向子執行緒傳遞引數 （同一個執行緒的實現方案正常是用ThreadLocal）
以下例子就是通過TaskDecorator實現日誌TraceID傳遞
@Component
public class MdcFilter extends GenericFilterBean {
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
throws IOException, ServletException {
try {
MDC.put("mdcData", "[userId:Duke]");
chain.doFilter(request, response);
} finally {
MDC.clear();
}
}
}
@EnableAsync(proxyTargetClass = true)
@SpringBootApplication
public class Application extends AsyncConfigurerSupport {
@Override
public Executor getAsyncExecutor() {
ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
executor.setTaskDecorator(new MdcTaskDecorator());
executor.initialize();
return executor;
}
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
}
class MdcTaskDecorator implements TaskDecorator {
@Override
public Runnable decorate(Runnable runnable) {
// Right now: Web thread context !
// (Grab the current thread MDC data)
Map<String, String> contextMap = MDC.getCopyOfContextMap();
return () -> {
try {
// Right now: @Async thread context !
// (Restore the Web thread context's MDC data)
MDC.setContextMap(contextMap);
runnable.run();
} finally {
MDC.clear();
}
};
}
}