如何保证在开始IntegrationFlow 的下一步之前完成该工作？

Question

我有以下流声明：

return flow -> flow.handle(myHandler)                
                .handle(springBatchJobLauncher)              
                .gateway(acknowledgementFlow);

启动器如下所示：

@ServiceActivator
public JobExecution launch(JobLaunchRequest request) throws JobExecutionException {
    Job job = request.getJob();
    JobParameters jobParameters = request.getJobParameters();

    return jobLauncher.run(job, jobParameters);
}

springBatchJobLauncher 开始的工作完成后，我需要立即开始acknowledgementFlow。按照这个配置有保障吗？

Answer 1

让我们来看看JobLauncher.run()JavaDocs！

 * Start a job execution for the given {@link Job} and {@link JobParameters}
 * . If a {@link JobExecution} was able to be created successfully, it will
 * always be returned by this method, regardless of whether or not the
 * execution was successful. If there is a past {@link JobExecution} which
 * has paused, the same {@link JobExecution} is returned instead of a new
 * one created. A exception will only be thrown if there is a failure to
 * start the job. If the job encounters some error while processing, the
 * JobExecution will be returned, and the status will need to be inspected.

因此，如果作业已成功启动，您将获得一个JobExecution 对象，但这确实与您的作业是否完成无关。为了这个目标，我相信我们需要有类似JobExecutionListener 的钩子。

在 Spring Batch 文档中查看更多信息：https://docs.spring.io/spring-batch/4.2.x/reference/html/spring-batch-integration.html#providing-feedback-with-informational-messages

step 有一个示例：

@MessagingGateway(name = "notificationExecutionsListener", defaultRequestChannel = "stepExecutionsChannel")
public interface NotificationExecutionListener extends StepExecutionListener {}

但同样的方法可以应用于JobExecutionListener。

因此，您需要将您的流程分成两部分，并让您的 .gateway(acknowledgementFlow) 仅从您的工作中执行的 afterJob(JobExecution jobExecution) 调用。