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Oracle Certified Professional: Java SE Developer 1Z0-831 (Java SE 25) · Domain 6: Working with streams and lambda expressions

Stream Gatherers (Java 24+): gather() with Gatherers.windowFixed, windowSliding, fold, scan

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Last reviewed September 25, 2026 · Leer en español

Stream Gatherers were finalized in Java 24. They add one new intermediate operation, Stream.gather(Gatherer), that lets you plug in custom transformations the built-in operations cannot express, such as grouping neighbors into windows or emitting running totals. Where collect with a Collector is a flexible terminal operation, gather with a Gatherer is a flexible intermediate operation: the stream continues afterwards.

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