import org.apache.flink.core.io.InputSplitAssigner; //导入依赖的package包/类
@Override
public InputSplit requestNextInputSplit(JobID jobID, JobVertexID vertexId, ExecutionAttemptID executionAttempt) throws IOException {

	final ExecutionGraph graph = this.currentJobs.get(jobID);
	if (graph == null) {
		LOG.error("Cannot find execution graph to job ID " + jobID);
		return null;
	}

	final ExecutionJobVertex vertex = graph.getJobVertex(vertexId);
	if (vertex == null) {
		LOG.error("Cannot find execution vertex for vertex ID " + vertexId);
		return null;
	}

	InputSplitAssigner splitAssigner = vertex.getSplitAssigner();
	if (splitAssigner == null) {
		LOG.error("No InputSplitAssigner for vertex ID " + vertexId);
		return null;
	}
	
	// get hostname for input split assignment
	String host = null;
	Execution execution = graph.getRegisteredExecutions().get(executionAttempt);
	if(execution == null) {
		LOG.error("Can not find Execution for attempt " + executionAttempt);
	} else {
		AllocatedSlot slot = execution.getAssignedResource();
		if(slot != null) {
			host = slot.getInstance().getInstanceConnectionInfo().getHostname();
		}
	}
	
	return splitAssigner.getNextInputSplit(host);
}
 

import org.apache.flink.core.io.InputSplitAssigner; //导入依赖的package包/类
@Override
public InputSplitAssigner getInputSplitAssigner(TweetFileInputSplit[] inputSplits) {
    return new DefaultInputSplitAssigner(inputSplits);
}
 

import org.apache.flink.core.io.InputSplitAssigner; //导入依赖的package包/类
@Override
public InputSplitAssigner getInputSplitAssigner(PravegaInputSplit[] inputSplits) {
    return new DefaultInputSplitAssigner(inputSplits);
}
 

import org.apache.flink.core.io.InputSplitAssigner; //导入依赖的package包/类
@Override
public InputSplitAssigner getInputSplitAssigner(final SourceInputSplit[] sourceInputSplits) {
  return new DefaultInputSplitAssigner(sourceInputSplits);
}
 

import org.apache.flink.core.io.InputSplitAssigner; //导入依赖的package包/类
@Override
public InputSplitAssigner getInputSplitAssigner(InputSplit[] inputSplits) {
	return new DefaultInputSplitAssigner(inputSplits);
}
 

import org.apache.flink.core.io.InputSplitAssigner; //导入依赖的package包/类
@Override
public InputSplitAssigner getInputSplitAssigner(HadoopInputSplit[] inputSplits) {
	return new LocatableInputSplitAssigner(inputSplits);
}
 

import org.apache.flink.core.io.InputSplitAssigner; //导入依赖的package包/类
@Override
public InputSplitAssigner getInputSplitAssigner(TableInputSplit[] inputSplits) {
	return new LocatableInputSplitAssigner(inputSplits);
}
 

import org.apache.flink.core.io.InputSplitAssigner; //导入依赖的package包/类
@Override
public InputSplitAssigner getInputSplitAssigner(CustomInputSplit[] inputSplits) {
	return new CustomSplitAssigner(inputSplits);
}
 

import org.apache.flink.core.io.InputSplitAssigner; //导入依赖的package包/类
@Override
public InputSplitAssigner getInputSplitAssigner(S[] inputSplits) {
	return new ReplicatingInputSplitAssigner(inputSplits);
}
 

import org.apache.flink.core.io.InputSplitAssigner; //导入依赖的package包/类
@Override
public CompletableFuture<SerializedInputSplit> requestNextInputSplit(
		final JobVertexID vertexID,
		final ExecutionAttemptID executionAttempt) {

	final Execution execution = executionGraph.getRegisteredExecutions().get(executionAttempt);
	if (execution == null) {
		// can happen when JobManager had already unregistered this execution upon on task failure,
		// but TaskManager get some delay to aware of that situation
		if (log.isDebugEnabled()) {
			log.debug("Can not find Execution for attempt {}.", executionAttempt);
		}
		// but we should TaskManager be aware of this
		return FutureUtils.completedExceptionally(new Exception("Can not find Execution for attempt " + executionAttempt));
	}

	final ExecutionJobVertex vertex = executionGraph.getJobVertex(vertexID);
	if (vertex == null) {
		log.error("Cannot find execution vertex for vertex ID {}.", vertexID);
		return FutureUtils.completedExceptionally(new Exception("Cannot find execution vertex for vertex ID " + vertexID));
	}

	final InputSplitAssigner splitAssigner = vertex.getSplitAssigner();
	if (splitAssigner == null) {
		log.error("No InputSplitAssigner for vertex ID {}.", vertexID);
		return FutureUtils.completedExceptionally(new Exception("No InputSplitAssigner for vertex ID " + vertexID));
	}

	final LogicalSlot slot = execution.getAssignedResource();
	final int taskId = execution.getVertex().getParallelSubtaskIndex();
	final String host = slot != null ? slot.getTaskManagerLocation().getHostname() : null;
	final InputSplit nextInputSplit = splitAssigner.getNextInputSplit(host, taskId);

	if (log.isDebugEnabled()) {
		log.debug("Send next input split {}.", nextInputSplit);
	}

	try {
		final byte[] serializedInputSplit = InstantiationUtil.serializeObject(nextInputSplit);
		return CompletableFuture.completedFuture(new SerializedInputSplit(serializedInputSplit));
	} catch (Exception ex) {
		log.error("Could not serialize the next input split of class {}.", nextInputSplit.getClass(), ex);
		IOException reason = new IOException("Could not serialize the next input split of class " +
				nextInputSplit.getClass() + ".", ex);
		vertex.fail(reason);
		return FutureUtils.completedExceptionally(reason);
	}
}
 

import org.apache.flink.core.io.InputSplitAssigner; //导入依赖的package包/类
public InputSplitAssigner getSplitAssigner() {
	return splitAssigner;
}
 

import org.apache.flink.core.io.InputSplitAssigner; //导入依赖的package包/类
@Override
public InputSplitAssigner getInputSplitAssigner(InputSplit[] inputSplits) {
	return null;
}
 

import org.apache.flink.core.io.InputSplitAssigner; //导入依赖的package包/类
@Override
public InputSplitAssigner getInputSplitAssigner(FileCopyTaskInputSplit[] inputSplits) {
	return new FileCopyTaskAssigner(inputSplits);
}
 

import org.apache.flink.core.io.InputSplitAssigner; //导入依赖的package包/类
@Override
public InputSplitAssigner getInputSplitAssigner(HadoopInputSplit[] inputSplits) {
	return new DefaultInputSplitAssigner(inputSplits);
}
 

import org.apache.flink.core.io.InputSplitAssigner; //导入依赖的package包/类
/**
 * Gets the type of the input splits that are processed by this input format.
 * 
 * @return The type of the input splits.
 */
@Override
InputSplitAssigner getInputSplitAssigner(T[] inputSplits);