Package org.apache.flink.streaming.api.datastream

Class DataStreamUtils

  • @Experimental
public final class DataStreamUtils
extends Object
    A collection of utilities for DataStreams.

    • Method Detail

      • collect

        @Deprecated
public static <OUT> Iterator<OUT> collect​(DataStream<OUT> stream)
        Deprecated.
        Please use DataStream.executeAndCollect().
        Triggers the distributed execution of the streaming dataflow and returns an iterator over the elements of the given DataStream.

        The DataStream application is executed in the regular distributed manner on the target environment, and the events from the stream are polled back to this application process and thread through Flink's REST API.

      • collect

        @Deprecated
public static <OUT> Iterator<OUT> collect​(DataStream<OUT> stream,
                                          String executionJobName)
        Deprecated.
        Please use DataStream.executeAndCollect().
        Triggers the distributed execution of the streaming dataflow and returns an iterator over the elements of the given DataStream.

        The DataStream application is executed in the regular distributed manner on the target environment, and the events from the stream are polled back to this application process and thread through Flink's REST API.

      • collectBoundedStream

        @Deprecated
public static <E> List<E> collectBoundedStream​(DataStream<E> stream,
                                               String jobName)
                                        throws Exception
        Deprecated.
        Please use DataStream.executeAndCollect().
        Collects contents the given DataStream into a list, assuming that the stream is a bounded stream.

        This method blocks until the job execution is complete. By the time the method returns, the job will have reached its FINISHED status.

        Note that if the stream is unbounded, this method will never return and might fail with an Out-of-Memory Error because it attempts to collect an infinite stream into a list.

        Throws:
        Exception - Exceptions that occur during the execution are forwarded.

      • collectUnboundedStream

        @Deprecated
public static <E> List<E> collectUnboundedStream​(DataStream<E> stream,
                                                 int numElements,
                                                 String jobName)
                                          throws Exception
        Deprecated.
        Please use DataStream.executeAndCollect().
        Triggers execution of the DataStream application and collects the given number of records from the stream. After the records are received, the execution is canceled.
        Throws:
        Exception

      • reinterpretAsKeyedStream

        public static <T,​K> KeyedStream<T,​K> reinterpretAsKeyedStream​(DataStream<T> stream,
                                                                          org.apache.flink.api.java.functions.KeySelector<T,​K> keySelector)
        Reinterprets the given DataStream as a KeyedStream, which extracts keys with the given KeySelector.

        IMPORTANT: For every partition of the base stream, the keys of events in the base stream must be partitioned exactly in the same way as if it was created through a DataStream.keyBy(KeySelector).

        Type Parameters:
        T - Type of events in the data stream.
        K - Type of the extracted keys.
        Parameters:
        stream - The data stream to reinterpret. For every partition, this stream must be partitioned exactly in the same way as if it was created through a DataStream.keyBy(KeySelector).
        keySelector - Function that defines how keys are extracted from the data stream.
        Returns:
        The reinterpretation of the DataStream as a KeyedStream.

      • reinterpretAsKeyedStream

        public static <T,​K> KeyedStream<T,​K> reinterpretAsKeyedStream​(DataStream<T> stream,
                                                                          org.apache.flink.api.java.functions.KeySelector<T,​K> keySelector,
                                                                          org.apache.flink.api.common.typeinfo.TypeInformation<K> typeInfo)
        Reinterprets the given DataStream as a KeyedStream, which extracts keys with the given KeySelector.

        IMPORTANT: For every partition of the base stream, the keys of events in the base stream must be partitioned exactly in the same way as if it was created through a DataStream.keyBy(KeySelector).

        Type Parameters:
        T - Type of events in the data stream.
        K - Type of the extracted keys.
        Parameters:
        stream - The data stream to reinterpret. For every partition, this stream must be partitioned exactly in the same way as if it was created through a DataStream.keyBy(KeySelector).
        keySelector - Function that defines how keys are extracted from the data stream.
        typeInfo - Explicit type information about the key type.
        Returns:
        The reinterpretation of the DataStream as a KeyedStream.