java-migratelisted

Guide the migration of a Java project to a newer Java version. This is an interactive migration assistant. ## Step 1 — Detect current version Check `pom.xml` (`<java.version>`, `<maven.compiler.source>`, `<maven.compiler.target>`) or `build.gradle` (`sourceCompatibility`, `javaVersion`). Ask for target version if not specified. ## Step 2 — Build the migration checklist ### Java 8 → Java 11 **Breaking changes to fix:** - Remove `sun.*` and `com.sun.*` internal API usage → find public alternatives - Remove JavaEE modules now removed from JDK: `javax.xml.bind` (JAXB), `javax.activation`, `javax.annotation` → add as Maven dependencies (`jakarta.xml.bind-api`, etc.) - Fix `ClassLoader.getSystemClassLoader().getResourceAsStream()` → use `getClass().getResourceAsStream()` - Flag use of `finalize()` → deprecated, suggest `Cleaner` or try-with-resources **Quick wins to adopt (optional):** - `var` for local variables (Java 10+) where type is obvious - `List.of()`, `Map.of()`, `Set.of()` instead of `Collections.unmodifiableList(Arrays.asList(...))` - `String` new methods: `isBlank()`, `strip()`, `lines()`, `repeat()` - `Optional.ifPresentOrElse()`, `Optional.or()` **Build changes:** ```xml <maven.compiler.source>11</maven.compiler.source> <maven.compiler.target>11</maven.compiler.target> ``` ### Java 11 → Java 17 **Breaking changes to fix:** - Strong encapsulation of JDK internals — fix any `--add-opens` flags (may need library updates) - Remove deprecated `SecurityManager` usage