← Exit to Module 10: Functional Programming and Streams lessons
Module progress · 0%Lesson · 18 min
Module 10: Functional Programming and Streams
Lesson focusCollectors In Depth
Compose downstream collectors to build complex aggregations.
01 · 15 minLambda Syntax VariationsLocked02 · 18 minBuilt-in Functional InterfacesLocked03 · 16 minStream Creation StrategiesLocked04 · 20 minIntermediate OperationsLocked05 · 22 minTerminal Operations & CollectorsLocked06 · 18 minCollectors In DepthLocked07 · 15 minParallel Streams BasicsLocked08 · 14 minFunctional Best PracticesLocked09 · 35 minMini-Project: Data Analysis with StreamsLocked
Combine groupingBy with downstream collectors like mapping, counting, or reducing.
Use teeing (Java 12+) to merge results from two collectors into a final object.
Write custom collectors when built-ins do not fit, implementing supplier, accumulator, combiner, finisher, and characteristics.