ContinuousFileMonitoringFunction.@Internal @Deprecated public class FileMonitoringFunction extends Object implements SourceFunction<org.apache.flink.api.java.tuple.Tuple3<String,Long,Long>>
SourceFunction that monitors a directory and sends events downstream when it detects
new files. Used together with FileReadFunction.| 限定符和类型 | 类和说明 |
|---|---|
static class |
FileMonitoringFunction.WatchType
已过时。
The watch type of the
FileMonitoringFunction. |
SourceFunction.SourceContext<T>| 构造器和说明 |
|---|
FileMonitoringFunction(String path,
long interval,
FileMonitoringFunction.WatchType watchType)
已过时。
|
public FileMonitoringFunction(String path, long interval, FileMonitoringFunction.WatchType watchType)
public void run(SourceFunction.SourceContext<org.apache.flink.api.java.tuple.Tuple3<String,Long,Long>> ctx) throws Exception
SourceFunctionSourceFunction.SourceContext to emit elements. Sources
that checkpoint their state for fault tolerance should use the SourceFunction.SourceContext.getCheckpointLock() checkpoint lock} to ensure consistency between the
bookkeeping and emitting the elements.
Sources that implement CheckpointedFunction must lock on the SourceFunction.SourceContext.getCheckpointLock() checkpoint lock} checkpoint lock (using a synchronized
block) before updating internal state and emitting elements, to make both an atomic
operation.
Refer to the top-level class docs for an example.
public void cancel()
SourceFunctionSourceFunction.run(SourceContext) method. The implementation needs to ensure that the source will break
out of that loop after this method is called.
A typical pattern is to have an "volatile boolean isRunning" flag that is set to
false in this method. That flag is checked in the loop condition.
In case of an ungraceful shutdown (cancellation of the source operator, possibly for
failover), the thread that calls SourceFunction.run(SourceContext) will also be interrupted) by the Flink runtime, in order to speed up the cancellation
(to ensure threads exit blocking methods fast, like I/O, blocking queues, etc.). The
interruption happens strictly after this method has been called, so any interruption handler
can rely on the fact that this method has completed (for example to ignore exceptions that
happen after cancellation).
During graceful shutdown (for example stopping a job with a savepoint), the program must
cleanly exit the SourceFunction.run(SourceContext) method soon after this method was called. The
Flink runtime will NOT interrupt the source thread during graceful shutdown. Source
implementors must ensure that no thread interruption happens on any thread that emits records
through the SourceContext from the SourceFunction.run(SourceContext) method; otherwise the
clean shutdown may fail when threads are interrupted while processing the final records.
Because the SourceFunction cannot easily differentiate whether the shutdown should
be graceful or ungraceful, we recommend that implementors refrain from interrupting any
threads that interact with the SourceContext at all. You can rely on the Flink
runtime to interrupt the source thread in case of ungraceful cancellation. Any additionally
spawned threads that directly emit records through the SourceContext should use a
shutdown method that does not rely on thread interruption.
cancel 在接口中 SourceFunction<org.apache.flink.api.java.tuple.Tuple3<String,Long,Long>>Copyright © 2014–2023 The Apache Software Foundation. All rights reserved.