Spring Boot启动时无法顺序运行几种方法

问题描述

应用程序启动时，我必须运行一些方法，如下所示：

@SpringBootApplication
public class Application implements CommandLineRunner {

    private final MonitoringService monitoringService;
    private final QrReaderServer qrReaderServer;

    @Override
    public void run(String... args) {
        monitoringService.launchMonitoring();
        qrReaderServer.launchServer();
    }

但是，只有第一个被执行！然后启动应用程序：

... Started Application in 5.21 seconds (JVM running for 6.336)
... START_MONITORING for folder: D:\results

第二个总是被跳过！

如果更改呼叫顺序-将仅执行第二个呼叫。

找不到一开始就启动的任何解决方案-尝试过@postconstruct，ApplicationRunner，@EventListener(ApplicationReadyEvent.class) ...

看起来他们以某种方式互相阻碍。尽管 都具有空类型 。

监视启动实施：

@Override
public void launchMonitoring() {
    log.info("START_MONITORING for folder: {}",monitoringProperties.getFolder());
    try {
        WatchKey key;
        while ((key = watchService.take()) != null) {
            for (WatchEvent<?> event : key.pollEvents()) {

                WatchEvent.Kind<?> kind = event.kind();

                if (kind == ENTRY_CREATE) {
                    log.info("FILE_CREATED: {}",event.context());

                    // some delay for fully file upload
                    Thread.sleep(monitoringProperties.getFrequency());

                    String fullFileName = getFileName(event);
                    String fileName = FilenameUtils.removeExtension(fullFileName);

                    processResource(fullFileName,fileName);
                }
            }
            key.reset();
        }
    } catch (InterruptedException e) {
        log.error("interrupted exception for monitoring service",e);
    } catch (IOException e) {
        log.error("io exception while processing file",e);
    } 
}

QR Reader启动（使用Netty配置启动TCP服务器）：

@Override
public void launchServer() {
    try {
        ChannelFuture serverChannelFuture = serverBootstrap.bind(hostAddress).sync();
        log.info("Server is STARTED : port {}",hostAddress.getPort());

        serverChannel = serverChannelFuture.channel().closeFuture().sync().channel();
    } catch (InterruptedException e) {
        Thread.currentThread().interrupt();
    } finally {
        shutdownQuietly();
    }
}

如何解决此问题？

解决方法

异步启动launchMonitoring()。

最简单的方法是在应用程序上添加@EnableAsync以启用异步 然后用launchMonitoring()注释@Async

不确定launchServer()是否也应该异步启动。

编辑：完成的答案

No task executor bean found for async processing: no bean of type TaskExecutor and no bean named 'taskExecutor' either

默认情况下，Spring将创建一个SimpleAsyncTaskExecutor，但是您可以提供taskExecutor

示例：

 @EnableAsync
 @Configuration
 public class AsyncConfig implements AsyncConfigurer {

     @Override
     public Executor getAsyncExecutor() {
         ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
         executor.set... // your custom configs
         executor.initialize();
         return executor;
     }

    ...
 }