最初我有以下配置：
@Configuration
public class ParallelFlowConfig {
@Autowired
private JobBuilderFactory jobBuilderFactory;
@Autowired
private StepBuilderFactory stepBuilderFactory;
@Bean
public Tasklet tasklet() {
return new CountingTasklet();
}
@Bean
public Flow syncFlow() {
return new FlowBuilder<Flow>("sync_flow")
.start(stepBuilderFactory.get("sync_flow_step1")
.tasklet(tasklet())
.build())
.next(stepBuilderFactory.get("sync_flow_step2")
.tasklet(tasklet())
//.taskExecutor(new SimpleAsyncTaskExecutor()) I am going to uncomment this line
.build())
.build();
}
@Bean
public Flow parallelFlow1() {
return new FlowBuilder<Flow>("async_flow_1")
.start(stepBuilderFactory.get("async_flow_1_step_1")
.tasklet(tasklet()).build())
.build();
}
@Bean
public Flow parallelFlow2() {
return new FlowBuilder<Flow>("async_flow_2")
.start(stepBuilderFactory.get("async_flow_2_step_1")
.tasklet(tasklet())
.build())
.next(stepBuilderFactory.get("async_flow_2_step_2")
.tasklet(tasklet())
.build())
.build();
}
@Bean
public Flow wrapperFlow(TaskExecutor jobTaskExecutor) {
return new FlowBuilder<Flow>("wrapperFlow")
.start(parallelFlow1())
.split(jobTaskExecutor)
.add(parallelFlow2())
.build();
}
@Bean
public Job parallelJob(TaskExecutor jobTaskExecutor) {
return jobBuilderFactory.get("sync_async_investigation_test")
.incrementer(new RunIdIncrementer())
.start(syncFlow())
.next(wrapperFlow(jobTaskExecutor))
.end()
.build();
}
public static class CountingTasklet implements Tasklet {
private final Logger logger = LoggerFactory.getLogger(CountingTasklet.class);
@Override
public RepeatStatus execute(StepContribution stepContribution, ChunkContext chunkContext) throws Exception {
logger.info("BEFORE {} has been executed on thread {}", chunkContext.getStepContext().getStepName(), Thread.currentThread().getName());
Thread.sleep(5000);
logger.info("AFTER {} has been executed on thread {}", chunkContext.getStepContext().getStepName(), Thread.currentThread().getName());
return RepeatStatus.FINISHED;
}
}
}
但是在这种情况下，sync_flow_step1和sync_flow_step2在主线程中执行。因此，我试图找到一个提供taskExecutor的地方，而我做了这么小的改动”：
@Bean
public Flow syncFlow() {
return new FlowBuilder<Flow>("sync_flow")
.start(stepBuilderFactory.get("sync_flow_step1")
.tasklet(tasklet())
.build())
.next(stepBuilderFactory.get("sync_flow_step2")
.tasklet(tasklet())
.taskExecutor(new SimpleAsyncTaskExecutor()) // <-- this line was added
.build())
.build();
}
添加之后，我发现sync_flow_step2被执行了4次（请搜索“ BEFORE sync_flow_step2”之前）：
2019-08-08 16:15:23.659 INFO 12436 --- [ main] h.w.c.ParallelFlowConfig$CountingTasklet : BEFORE sync_flow_step1 has been executed on thread main
2019-08-08 16:15:28.659 INFO 12436 --- [ main] h.w.c.ParallelFlowConfig$CountingTasklet : AFTER sync_flow_step1 has been executed on thread main
2019-08-08 16:15:28.659 DEBUG 12436 --- [ main] o.s.batch.core.step.tasklet.TaskletStep : Applying contribution: [StepContribution: read=0, written=0, filtered=0, readSkips=0, writeSkips=0, processSkips=0, exitStatus=EXECUTING]
2019-08-08 16:15:28.661 DEBUG 12436 --- [ main] o.s.batch.core.step.tasklet.TaskletStep : Saving step execution before commit: StepExecution: id=6925, version=1, name=sync_flow_step1, status=STARTED, exitStatus=EXECUTING, readCount=0, filterCount=0, writeCount=0 readSkipCount=0, writeSkipCount=0, processSkipCount=0, commitCount=1, rollbackCount=0, exitDescription=
2019-08-08 16:15:28.663 DEBUG 12436 --- [ main] o.s.batch.core.step.AbstractStep : Step execution success: id=6925
2019-08-08 16:15:28.667 DEBUG 12436 --- [ main] o.s.batch.core.step.AbstractStep : Step execution complete: StepExecution: id=6925, version=3, name=sync_flow_step1, status=COMPLETED, exitStatus=COMPLETED, readCount=0, filterCount=0, writeCount=0 readSkipCount=0, writeSkipCount=0, processSkipCount=0, commitCount=1, rollbackCount=0
2019-08-08 16:15:28.669 DEBUG 12436 --- [ main] o.s.b.core.job.flow.support.SimpleFlow : Completed state=sync_flow.sync_flow_step1 with status=COMPLETED
2019-08-08 16:15:28.669 DEBUG 12436 --- [ main] o.s.b.core.job.flow.support.SimpleFlow : Handling state=sync_flow.sync_flow_step2
2019-08-08 16:15:28.684 INFO 12436 --- [ main] o.s.batch.core.job.SimpleStepHandler : Executing step: [sync_flow_step2]
2019-08-08 16:15:28.684 DEBUG 12436 --- [ main] o.s.batch.core.step.AbstractStep : Executing: id=6926
2019-08-08 16:15:28.687 DEBUG 12436 --- [ main] o.s.b.r.s.TaskExecutorRepeatTemplate : Starting repeat context.
2019-08-08 16:15:28.692 DEBUG 12436 --- [cTaskExecutor-2] o.s.b.r.s.TaskExecutorRepeatTemplate : Repeat operation about to start at count=4
2019-08-08 16:15:28.692 DEBUG 12436 --- [cTaskExecutor-1] o.s.b.r.s.TaskExecutorRepeatTemplate : Repeat operation about to start at count=4
2019-08-08 16:15:28.692 DEBUG 12436 --- [cTaskExecutor-2] o.s.b.c.s.c.StepContextRepeatCallback : Preparing chunk execution for StepContext: org.springframework.batch.core.scope.context.StepContext@6b7075ed
2019-08-08 16:15:28.692 DEBUG 12436 --- [cTaskExecutor-2] o.s.b.c.s.c.StepContextRepeatCallback : Chunk execution starting: queue size=0
2019-08-08 16:15:28.692 DEBUG 12436 --- [cTaskExecutor-1] o.s.b.c.s.c.StepContextRepeatCallback : Preparing chunk execution for StepContext: org.springframework.batch.core.scope.context.StepContext@6b7075ed
2019-08-08 16:15:28.692 DEBUG 12436 --- [cTaskExecutor-1] o.s.b.c.s.c.StepContextRepeatCallback : Chunk execution starting: queue size=0
2019-08-08 16:15:28.692 DEBUG 12436 --- [cTaskExecutor-4] o.s.b.r.s.TaskExecutorRepeatTemplate : Repeat operation about to start at count=4
2019-08-08 16:15:28.692 INFO 12436 --- [cTaskExecutor-2] h.w.c.ParallelFlowConfig$CountingTasklet : BEFORE sync_flow_step2 has been executed on thread SimpleAsyncTaskExecutor-2
2019-08-08 16:15:28.692 DEBUG 12436 --- [cTaskExecutor-4] o.s.b.c.s.c.StepContextRepeatCallback : Preparing chunk execution for StepContext: org.springframework.batch.core.scope.context.StepContext@6b7075ed
2019-08-08 16:15:28.692 DEBUG 12436 --- [cTaskExecutor-4] o.s.b.c.s.c.StepContextRepeatCallback : Chunk execution starting: queue size=0
2019-08-08 16:15:28.692 DEBUG 12436 --- [cTaskExecutor-3] o.s.b.r.s.TaskExecutorRepeatTemplate : Repeat operation about to start at count=4
2019-08-08 16:15:28.693 INFO 12436 --- [cTaskExecutor-1] h.w.c.ParallelFlowConfig$CountingTasklet : BEFORE sync_flow_step2 has been executed on thread SimpleAsyncTaskExecutor-1
2019-08-08 16:15:28.693 INFO 12436 --- [cTaskExecutor-4] h.w.c.ParallelFlowConfig$CountingTasklet : BEFORE sync_flow_step2 has been executed on thread SimpleAsyncTaskExecutor-4
2019-08-08 16:15:28.693 DEBUG 12436 --- [cTaskExecutor-3] o.s.b.c.s.c.StepContextRepeatCallback : Preparing chunk execution for StepContext: org.springframework.batch.core.scope.context.StepContext@6b7075ed
2019-08-08 16:15:28.693 DEBUG 12436 --- [cTaskExecutor-3] o.s.b.c.s.c.StepContextRepeatCallback : Chunk execution starting: queue size=0
2019-08-08 16:15:28.694 INFO 12436 --- [cTaskExecutor-3] h.w.c.ParallelFlowConfig$CountingTasklet : BEFORE sync_flow_step2 has been executed on thread SimpleAsyncTaskExecutor-3
2019-08-08 16:15:33.692 INFO 12436 --- [cTaskExecutor-2] h.w.c.ParallelFlowConfig$CountingTasklet : AFTER sync_flow_step2 has been executed on thread SimpleAsyncTaskExecutor-2
2019-08-08 16:15:33.692 DEBUG 12436 --- [cTaskExecutor-2] o.s.batch.core.step.tasklet.TaskletStep : Applying contribution: [StepContribution: read=0, written=0, filtered=0, readSkips=0, writeSkips=0, processSkips=0, exitStatus=EXECUTING]
2019-08-08 16:15:33.693 INFO 12436 --- [cTaskExecutor-1] h.w.c.ParallelFlowConfig$CountingTasklet : AFTER sync_flow_step2 has been executed on thread SimpleAsyncTaskExecutor-1
2019-08-08 16:15:33.693 INFO 12436 --- [cTaskExecutor-4] h.w.c.ParallelFlowConfig$CountingTasklet : AFTER sync_flow_step2 has been executed on thread SimpleAsyncTaskExecutor-4
2019-08-08 16:15:33.694 INFO 12436 --- [cTaskExecutor-3] h.w.c.ParallelFlowConfig$CountingTasklet : AFTER sync_flow_step2 has been executed on thread SimpleAsyncTaskExecutor-3
为什么会发生？为什么是4个？
如何在单独的threadPool上运行sync_flow但没有步骤执行重复？
答案 0 :(得分：0)
根据您的日志，您如何参与TaskExecutorRepeatTemplate。此类的默认限制为4。
public class org.springframework.batch.repeat.support.TaskExecutorRepeatTemplate extends org.springframework.batch.repeat.support.RepeatTemplate {
// Field descriptor #47 I
public static final int DEFAULT_THROTTLE_LIMIT = 4;