Skip to main content

JVM

JVM-related helpers shipped by this repo — JDK switching and Maven OpenRewrite recipe runners.

Tip 23.1: JDK Switching​

jdk flips JAVA_HOME (and PATH) between Homebrew-installed OpenJDKs.

jdk 17           # switch to OpenJDK 17
jdk 21           # switch to OpenJDK 21
jdk              # show currently active JDK and available versions
echo $JAVA_HOME  # see where it pointed JAVA_HOME

Requires the matching openjdk@17 / openjdk@21 Homebrew formulae installed (already in init/31_homebrew_recipes.sh). From source/10_java.sh.

Tip 23.2: Maven OpenRewrite Recipes​

Run OpenRewrite refactoring recipes against the current Maven project. Useful for big migrations.

mvn-check-tests              # run the test suite, summarise pass/fail counts
mvn-rewrite-junit            # migrate JUnit 4 → JUnit 5
mvn-rewrite-asserts          # migrate Hamcrest/JUnit asserts → AssertJ
mvn-rewrite-runwith          # migrate @RunWith → @ExtendWith (JUnit 5)

These are thin wrappers around the corresponding mvn org.openrewrite.maven:rewrite-maven-plugin:run invocations, so the Maven project must have OpenRewrite available. From source/45_maven.sh.