public class RawInputFromCSVSpout extends BaseRichSpout
| Constructor and Description |
|---|
RawInputFromCSVSpout(File rawInputCsv,
List<String> outputFields) |
| Modifier and Type | Method and Description |
|---|---|
void |
activate()
Called when a spout has been activated out of a deactivated mode.
|
void |
close()
Called when an ISpout is going to be shutdown.
|
void |
deactivate()
Called when a spout has been deactivated.
|
void |
declareOutputFields(OutputFieldsDeclarer declarer)
Declare the output schema for all the streams of this topology.
|
static RawInputFromCSVSpout |
newInstance(File csv) |
void |
nextTuple()
When this method is called, Storm is requesting that the Spout emit tuples to the output collector.
|
void |
open(Map<String,Object> conf,
TopologyContext context,
SpoutOutputCollector collector)
Called when a task for this component is initialized within a worker on the cluster.
|
ack, failgetComponentConfigurationclone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, waitgetComponentConfigurationpublic RawInputFromCSVSpout(File rawInputCsv, List<String> outputFields) throws FileNotFoundException
FileNotFoundExceptionpublic static RawInputFromCSVSpout newInstance(File csv) throws IOException
IOExceptionpublic void open(Map<String,Object> conf, TopologyContext context, SpoutOutputCollector collector)
ISpoutCalled when a task for this component is initialized within a worker on the cluster. It provides the spout with the environment in which the spout executes.
This includes the:
conf - The Storm configuration for this spout. This is the configuration provided to the topology merged in with cluster configuration on this machine.context - This object can be used to get information about this task’s place within the topology, including the task id and component id of this task, input and output information, etc.collector - The collector is used to emit tuples from this spout. Tuples can be emitted at any time, including the open and close methods. The collector is thread-safe and should be saved as an instance variable of this spout object.public void nextTuple()
ISpoutWhen this method is called, Storm is requesting that the Spout emit tuples to the output collector. This method should be non-blocking, so if the Spout has no tuples to emit, this method should return. nextTuple, ack, and fail are all called in a tight loop in a single thread in the spout task. When there are no tuples to emit, it is courteous to have nextTuple sleep for a short amount of time (like a single millisecond) so as not to waste too much CPU.
public void declareOutputFields(OutputFieldsDeclarer declarer)
IComponentDeclare the output schema for all the streams of this topology.
declarer - this is used to declare output stream ids, output fields, and whether or not each output stream is a direct streampublic void activate()
ISpoutCalled when a spout has been activated out of a deactivated mode. nextTuple will be called on this spout soon. A spout can become activated after having been deactivated when the topology is manipulated using the storm client.
activate in interface ISpoutactivate in class BaseRichSpoutpublic void deactivate()
ISpoutCalled when a spout has been deactivated. nextTuple will not be called while a spout is deactivated. The spout may or may not be reactivated in the future.
deactivate in interface ISpoutdeactivate in class BaseRichSpoutpublic void close()
ISpoutCalled when an ISpout is going to be shutdown. There is no guarentee that close will be called, because the supervisor kill -9’s worker processes on the cluster.
The one context where close is guaranteed to be called is a topology is killed when running Storm in local mode.
close in interface ISpoutclose in class BaseRichSpoutCopyright © 2021 The Apache Software Foundation. All rights reserved.