问题
I have setup File poller with task executor
ExecutorService executorService = Executors.newFixedThreadPool(10);
LOG.info("Setting up the poller for directory {} ", finalDirectory);
StandardIntegrationFlow standardIntegrationFlow = IntegrationFlows.from(new CustomFileReadingSource(finalDirectory),
c -> c.poller(Pollers.fixedDelay(5, TimeUnit.SECONDS, 5)
.taskExecutor(executorService)
.maxMessagesPerPoll(10)
.advice(new LoggerSourceAdvisor(finalDirectory))
))
//move file to processing first processing
.transform(new FileMoveTransformer("C:/processing", true))
.channel("fileRouter")
.get();
As seen I have setup fixed threadpool of 10 and maximum message 10 per poll. If I put 10 files it still processes one by one. What could be wrong here ?
* UPDATE *
It works perfectly fine after Gary's answer though I have other issue now.
I have setup my Poller like this
setDirectory(new File(path));
DefaultDirectoryScanner scanner = new DefaultDirectoryScanner();
scanner.setFilter(new AcceptAllFileListFilter<>());
setScanner(scanner);
The reason of using AcceptAll because the same file may come again that's why I sort of move the file first. But when I enable the thread executor the same file is being processed by mutliple threads, I assume because of AcceptAllFile
If I Change to AcceptOnceFileListFilter it works but then the same file that comes again will not be picked up again ! What can be done to avoid this issue ?
Issue/Bug
In Class AbstractPersistentAcceptOnceFileListFilter We have this code
@Override
public boolean accept(F file) {
String key = buildKey(file);
synchronized (this.monitor) {
String newValue = value(file);
String oldValue = this.store.putIfAbsent(key, newValue);
if (oldValue == null) { // not in store
flushIfNeeded();
return true;
}
// same value in store
if (!isEqual(file, oldValue) && this.store.replace(key, oldValue, newValue)) {
flushIfNeeded();
return true;
}
return false;
}
}
Now for example if I have setup max per poll 5 and there are two files then its possible same file would be picked up by two threads.
Lets say my code moves the files once I read it.
But the other thread gets to the accept method
if the file is not there then it will return lastModified time as 0 and it will return true.
That causes the issue because the file is NOT there.
If its 0 then it should return false as the file is not there anymore.
回答1:
When you add a task executor to a poller; all that does is the scheduler thread hands the poll task off to a thread in the thread pool; the maxMessagesPerPoll is part of the poll task. The poller itself only runs once every 5 seconds. To get what you want, you should add an executor channel to the flow...
@SpringBootApplication
public class So53521593Application {
private static final Logger logger = LoggerFactory.getLogger(So53521593Application.class);
public static void main(String[] args) {
SpringApplication.run(So53521593Application.class, args);
}
@Bean
public IntegrationFlow flow() {
ExecutorService exec = Executors.newFixedThreadPool(10);
return IntegrationFlows.from(() -> "foo", e -> e
.poller(Pollers.fixedDelay(5, TimeUnit.SECONDS)
.maxMessagesPerPoll(10)))
.channel(MessageChannels.executor(exec))
.<String>handle((p, h) -> {
try {
logger.info(p);
Thread.sleep(10_000);
}
catch (InterruptedException e1) {
Thread.currentThread().interrupt();
}
return null;
})
.get();
}
}
EDIT
It works fine for me...
@Bean
public IntegrationFlow flow() {
ExecutorService exec = Executors.newFixedThreadPool(10);
return IntegrationFlows.from(Files.inboundAdapter(new File("/tmp/foo")).filter(
new FileSystemPersistentAcceptOnceFileListFilter(new SimpleMetadataStore(), "foo")),
e -> e.poller(Pollers.fixedDelay(5, TimeUnit.SECONDS)
.maxMessagesPerPoll(10)))
.channel(MessageChannels.executor(exec))
.handle((p, h) -> {
try {
logger.info(p.toString());
Thread.sleep(10_000);
}
catch (InterruptedException e1) {
Thread.currentThread().interrupt();
}
return null;
})
.get();
}
and
2018-11-28 11:46:05.196 INFO 57607 --- [pool-1-thread-1] com.example.So53521593Application : /tmp/foo/test1.txt
2018-11-28 11:46:05.197 INFO 57607 --- [pool-1-thread-2] com.example.So53521593Application : /tmp/foo/test2.txt
and with touch test1.txt
2018-11-28 11:48:00.284 INFO 57607 --- [pool-1-thread-3] com.example.So53521593Application : /tmp/foo/test1.txt
EDIT1
Agreed - reproduced with this...
@Bean
public IntegrationFlow flow() {
ExecutorService exec = Executors.newFixedThreadPool(10);
return IntegrationFlows.from(Files.inboundAdapter(new File("/tmp/foo")).filter(
new FileSystemPersistentAcceptOnceFileListFilter(new SimpleMetadataStore(), "foo")),
e -> e.poller(Pollers.fixedDelay(5, TimeUnit.SECONDS)
.maxMessagesPerPoll(10)))
.channel(MessageChannels.executor(exec))
.<File>handle((p, h) -> {
try {
p.delete();
logger.info(p.toString());
Thread.sleep(10_000);
}
catch (InterruptedException e1) {
Thread.currentThread().interrupt();
}
return null;
})
.get();
}
and
2018-11-28 13:22:23.689 INFO 75681 --- [pool-1-thread-1] com.example.So53521593Application : /tmp/foo/test1.txt
2018-11-28 13:22:23.690 INFO 75681 --- [pool-1-thread-2] com.example.So53521593Application : /tmp/foo/test2.txt
2018-11-28 13:22:23.690 INFO 75681 --- [pool-1-thread-3] com.example.So53521593Application : /tmp/foo/test1.txt
2018-11-28 13:22:23.690 INFO 75681 --- [pool-1-thread-4] com.example.So53521593Application : /tmp/foo/test2.txt
来源：https://stackoverflow.com/questions/53521593/taskexecutor-is-not-working-spring-integration