Modern Java 21+: The Next-Level Upgrade
summary
Survey of Java 9–21 features with concrete examples: uses the built-in HTTP client and Jackson to call open-notify.org, parse JSON into records, and assert there are seven astronauts aboard the ISS; shows that the HTTP client is AutoCloseable in Java 21 so it can be used in a try-with-resources; models responses as a sealed interface Result with Success/Failure records and uses pattern matching for switch (GA in 21) to extract data; demos JShell, single-file execution, text blocks, and the tiny jweb server.
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chapters (8)
- 0:00Introduction to Java 21+
- 6:09Collection factory methods
- 11:08Local variable type inference
- 22:53HTTP client in Java 11
- 36:23Command line features
- 46:23Enhanced switch and text blocks
- 50:34Records and sealed interfaces
- 1:00:00Virtual threads and Java 21
