Level Up Your Java Streams with Gatherers
summary
Java 24 adds Stream Gatherers and the session shows concrete code: five default gatherers—window fixed and window sliding, scan and fold, plus mapConcurrent uses virtual threads—with demos on temperature sensor streams that compute hourly averages (windows of 60) and running averages. Examples include a zip-with-index gatherer using mutable state, IntelliJ’s “trace current stream chain” debugging, mapConcurrent with maxConcurrency=3 preserving order, and guidance to start with sequential gatherers before adding parallel support.
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chapters (14)
- 0:00From heat wave to Java streams
- 3:15Java streams recap
- 7:11Stream pipeline demo
- 11:24Limitations of standard streams
- 12:30Java 24 gatherers intro
- 15:19Fixed window gatherer
- 19:37Sliding window gatherer
- 21:24Scan and fold gatherers
- 27:51Map concurrent gatherer
- 29:15Custom gatherers from scratch
- 33:48Zip with index gatherer
- 38:23Sensor data challenges
- 39:25Gatherers summary
- 40:37Q&A
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