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

Class DataStreamUtils

java.lang.Object
org.apache.flink.streaming.api.datastream.DataStreamUtils
@Experimental public final class DataStreamUtils extends Object
A collection of utilities for DataStreams.

  • Method Summary

    Modifier and Type
    Method
    Description
    static <T, K> org.apache.flink.streaming.api.datastream.KeyedStream<T,K>
    reinterpretAsKeyedStream(org.apache.flink.streaming.api.datastream.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.
    static <T, K> org.apache.flink.streaming.api.datastream.KeyedStream<T,K>
    reinterpretAsKeyedStream(org.apache.flink.streaming.api.datastream.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.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Method Details

    • reinterpretAsKeyedStream

      public static <T, K> org.apache.flink.streaming.api.datastream.KeyedStream<T,K> reinterpretAsKeyedStream(org.apache.flink.streaming.api.datastream.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> org.apache.flink.streaming.api.datastream.KeyedStream<T,K> reinterpretAsKeyedStream(org.apache.flink.streaming.api.datastream.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.