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Java Evolution

Java releases a new LTS version every three years. Understanding what changed in each version — especially Java 8, 11, 17, and 21 — is critical for reading job postings, navigating legacy codebases, and demonstrating senior-level awareness. Interviewers regularly ask "what's new in Java 17/21?" as a quick filter.

What You'll Find Here

Notes are being added. Planned topics:

TopicDescription
Java 8 FeaturesLambdas, Streams, Optional, java.time, interface default methods.
Java 9–11 FeaturesJPMS modules, var (Java 10), HTTP Client (Java 11), String API additions.
Java 14–17 FeaturesRecords, sealed classes, pattern matching instanceof, text blocks, switch expressions.
Java 21 FeaturesVirtual threads (Project Loom), pattern matching for switch, sequenced collections, record patterns.

Learning Path

  1. Java 8 — most Java codebases target Java 8+; lambdas and streams are everywhere. Start here.
  2. Java 11 — the first LTS after Java 8; var, isBlank, HTTP Client, and List.of are commonly used.
  3. Java 17 — the LTS most teams run today; records and sealed classes reshape data modeling.
  4. Java 21 — the current LTS; virtual threads are a paradigm shift for high-throughput services.