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How to use Java 8 Stream Collectors.groupingBy() Examples

loizenai profile image loizenai ・1 min read

https://grokonez.com/java/java-8/how-to-use-java-8-stream-collectors-groupingby-examples

How to use Java 8 Stream Collectors.groupingBy() Examples

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In the tutorial, Grokonez will show how to use Grouping By APIs of Java Stream Collectors by examples:

  • Explore Stream GroupingBy Signatures
  • Combine groupingBy API with others Reduction Operations

Now let's do more details!

Related posts:

Stream GroupingBy Signatures

1. groupingBy(classifier)


public static  Collector>> groupingBy(Function super T,? extends K> classifier)

-> It returns a Collector implementing a group by operation on input elements of type T,
grouping elements according to a classifier function, and returning the results in a Map.

  • Type Parameters:
  • T - the type of the input elements
  • K - the type of the keys

  • Parameters:

  • classifier: the classifier function mapping input elements to keys

  • Returns: a Collector implementing the cascaded group-by operation

Example:

More at:

https://grokonez.com/java/java-8/how-to-use-java-8-stream-collectors-groupingby-examples

How to use Java 8 Stream Collectors.groupingBy() Examples

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