import org.apache.flink.api.common.io.RichInputFormat; //导入依赖的package包/类
private <OUT> List<OUT> executeDataSource(GenericDataSourceBase<?, ?> source, int superStep)
		throws Exception {
	@SuppressWarnings("unchecked")
	GenericDataSourceBase<OUT, ?> typedSource = (GenericDataSourceBase<OUT, ?>) source;
	// build the runtime context and compute broadcast variables, if necessary
	TaskInfo taskInfo = new TaskInfo(typedSource.getName(), 1, 0, 1, 0);
	
	RuntimeUDFContext ctx;

	MetricGroup metrics = new UnregisteredMetricsGroup();
	if (RichInputFormat.class.isAssignableFrom(typedSource.getUserCodeWrapper().getUserCodeClass())) {
		ctx = superStep == 0 ? new RuntimeUDFContext(taskInfo, classLoader, executionConfig, cachedFiles, accumulators, metrics) :
				new IterationRuntimeUDFContext(taskInfo, classLoader, executionConfig, cachedFiles, accumulators, metrics);
	} else {
		ctx = null;
	}
	return typedSource.executeOnCollections(ctx, executionConfig);
}
 

import org.apache.flink.api.common.io.RichInputFormat; //导入依赖的package包/类
protected List<OUT> executeOnCollections(RuntimeContext ctx, ExecutionConfig executionConfig) throws Exception {
	@SuppressWarnings("unchecked")
	InputFormat<OUT, InputSplit> inputFormat = (InputFormat<OUT, InputSplit>) this.formatWrapper.getUserCodeObject();
	//configure the input format
	inputFormat.configure(this.parameters);

	//open the input format
	if (inputFormat instanceof RichInputFormat) {
		((RichInputFormat) inputFormat).setRuntimeContext(ctx);
		((RichInputFormat) inputFormat).openInputFormat();
	}

	List<OUT> result = new ArrayList<OUT>();
	
	// splits
	InputSplit[] splits = inputFormat.createInputSplits(1);
	TypeSerializer<OUT> serializer = getOperatorInfo().getOutputType().createSerializer(executionConfig);
	
	for (InputSplit split : splits) {
		inputFormat.open(split);
		
		while (!inputFormat.reachedEnd()) {
			OUT next = inputFormat.nextRecord(serializer.createInstance());
			if (next != null) {
				result.add(serializer.copy(next));
			}
		}
		
		inputFormat.close();
	}
	
	//close the input format
	if (inputFormat instanceof RichInputFormat) {
		((RichInputFormat) inputFormat).closeInputFormat();
	}

	return result;
}
 

import org.apache.flink.api.common.io.RichInputFormat; //导入依赖的package包/类
@Override
@SuppressWarnings("unchecked")
public void open(Configuration parameters) throws Exception {
	StreamingRuntimeContext context = (StreamingRuntimeContext) getRuntimeContext();

	if (format instanceof RichInputFormat) {
		((RichInputFormat) format).setRuntimeContext(context);
	}
	format.configure(parameters);

	provider = context.getInputSplitProvider();
	serializer = typeInfo.createSerializer(getRuntimeContext().getExecutionConfig());
	splitIterator = getInputSplits();
	isRunning = splitIterator.hasNext();
}
 

import org.apache.flink.api.common.io.RichInputFormat; //导入依赖的package包/类
@Override
public void run(SourceContext<OUT> ctx) throws Exception {
	try {

		Counter completedSplitsCounter = getRuntimeContext().getMetricGroup().counter("numSplitsProcessed");
		if (isRunning && format instanceof RichInputFormat) {
			((RichInputFormat) format).openInputFormat();
		}

		OUT nextElement = serializer.createInstance();
		while (isRunning) {
			format.open(splitIterator.next());

			// for each element we also check if cancel
			// was called by checking the isRunning flag

			while (isRunning && !format.reachedEnd()) {
				nextElement = format.nextRecord(nextElement);
				if (nextElement != null) {
					ctx.collect(nextElement);
				} else {
					break;
				}
			}
			format.close();
			completedSplitsCounter.inc();

			if (isRunning) {
				isRunning = splitIterator.hasNext();
			}
		}
	} finally {
		format.close();
		if (format instanceof RichInputFormat) {
			((RichInputFormat) format).closeInputFormat();
		}
		isRunning = false;
	}
}
 

import org.apache.flink.api.common.io.RichInputFormat; //导入依赖的package包/类
@Override
public void close() throws Exception {
	format.close();
	if (format instanceof RichInputFormat) {
		((RichInputFormat) format).closeInputFormat();
	}
}