Collections Refueled
summary
JDK 9 adds convenience factory methods (JEP 269): List.of, Set.of, Map.of (Map.ofEntries + entry for >10 pairs) that return new private implementations which are unmodifiable, disallow nulls, and throw on duplicate keys at creation. Implementations prioritize space efficiency (two-element set ~20 bytes vs ~152 bytes for a wrapped HashSet), use a randomized iteration order per JVM start, serialize via a stable proxy, and prompt proposed copyOf/stream collectors for later releases.
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chapters (7)
- 0:00Start
- 3:43Java 9 - Collections Convenience Factory Methods
- 12:02Implementation Characteristics
- 21:17Randomized iteration Order
- 32:12Space Efficiency
- 38:18Serialization
- 43:30Summary
