Section 17.6.5 Grouping Employees By Department
• Collectors static method groupingBy (p. 755) with one argument receives a Function that classifies objects in the stream—the values returned by this function are used as the keys in a Map. The corresponding values, by default, are Lists containing the stream elements in a given category.
• Map method forEach performs an operation on each key–value pair. The method receives an object that implements functional interface BiConsumer. This interface’s accept method has two parameters. For Maps, the first represents the key and the second the corresponding value.
Get Java™ How To Program (Early Objects), Tenth Edition now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
