Examples with DataStreamSource org.apache.flink.streaming.api.datastream.DataStreamSource used on opensource projects

Example 1 with DataStreamSource

use of org.apache.flink.streaming.api.datastream.DataStreamSource in project flink by apache.

the class StreamExecutionEnvironment method addSource.

/**
	 * Ads a data source with a custom type information thus opening a
	 * {@link DataStream}. Only in very special cases does the user need to
	 * support type information. Otherwise use
	 * {@link #addSource(org.apache.flink.streaming.api.functions.source.SourceFunction)}
	 *
	 * @param function
	 * 		the user defined function
	 * @param sourceName
	 * 		Name of the data source
	 * @param <OUT>
	 * 		type of the returned stream
	 * @param typeInfo
	 * 		the user defined type information for the stream
	 * @return the data stream constructed
	 */
@SuppressWarnings("unchecked")
public <OUT> DataStreamSource<OUT> addSource(SourceFunction<OUT> function, String sourceName, TypeInformation<OUT> typeInfo) {
    if (typeInfo == null) {
        if (function instanceof ResultTypeQueryable) {
            typeInfo = ((ResultTypeQueryable<OUT>) function).getProducedType();
        } else {
            try {
                typeInfo = TypeExtractor.createTypeInfo(SourceFunction.class, function.getClass(), 0, null, null);
            } catch (final InvalidTypesException e) {
                typeInfo = (TypeInformation<OUT>) new MissingTypeInfo(sourceName, e);
            }
        }
    }
    boolean isParallel = function instanceof ParallelSourceFunction;
    clean(function);
    StreamSource<OUT, ?> sourceOperator;
    if (function instanceof StoppableFunction) {
        sourceOperator = new StoppableStreamSource<>(cast2StoppableSourceFunction(function));
    } else {
        sourceOperator = new StreamSource<>(function);
    }
    return new DataStreamSource<>(this, typeInfo, sourceOperator, isParallel, sourceName);
}