SDKMAN alternative on Windows for Java projects

If you need an SDKMAN alternative on Windows for installing and switching Java, jm provides a native PowerShell workflow. It can install JDKs, set a global default, switch Java per project, and read an existing .sdkmanrc Java entry.

This is a Java/JDK alternative, not a full SDKMAN replacement. jm does not install or switch Kotlin, Maven, Gradle, or other SDKMAN candidates, does not run sdk env, and does not consume SDKMAN's local installation catalog.

Install the Windows-native manager

On Windows x86-64, install with Scoop:

scoop bucket add shinnosuke0722 https://github.com/Shinnosuke0722/scoop-bucket
scoop install shinnosuke0722/jm

Then initialize the current PowerShell session and add the same command to $PROFILE for future sessions:

jm shell init powershell | Invoke-Expression

See the Windows JDK version manager guide for the PowerShell release installer, PATH troubleshooting, upgrades, and Windows ARM64 notes.

Supported Java entry

Given this file:

java=21.0.2-tem
kotlin=2.1.0

jm interprets the Java requirement as Temurin 21.0.2 and ignores the Kotlin line. The parser expects the exact java= key form; java = ... is not treated as a Java entry.

Recognized SDKMAN vendor suffix mappings include:

SDKMAN suffix	jm distribution
tem	temurin
amzn	corretto
zulu	zulu
oracle	oracle
librca	liberica
sapmchn	sapmachine
sem	semeru
graalce	graalvm-ce
graal	graalvm
ms	microsoft
mandrel	mandrel

Unknown suffixes are retained as candidate distribution names after normal validation. Project detection still checks only installed JDKs; it does not query or install packages. To attempt an installation, run jm install DIST-VERSION explicitly—for example, jm install custom-21. Availability depends on the upstream catalog and platform.

Safe migration workflow

1. Inspect the project's Java entry.

   grep '^java=' .sdkmanrc

   In PowerShell:

   Select-String -Path .sdkmanrc -Pattern '^java='

2. Install the corresponding JDK using jm's distribution-first syntax. For java=21.0.2-tem, use:

   jm install temurin-21.0.2

3. Enable the jm shell hook, enter the project, and verify both the detected requirement and running Java:

   jm current
   java -version

4. Keep .sdkmanrc if SDKMAN users or other SDK candidates still depend on it. jm and SDKMAN should not both own the same shell's Java switching hook at the same time; choose one manager per active shell to avoid competing PATH and JAVA_HOME changes.

5. If the project is moving fully to jm, write a dedicated file:

   jm use temurin-21.0.2

   This creates .java-version with the full installed ID. Once the team has agreed on the migration, remove only the obsolete Java entry—or the whole .sdkmanrc if no other SDKMAN candidates use it.

Resolution details

• When .java-version and .sdkmanrc are in the same directory, .java-version wins.
• A nearer .sdkmanrc can win over a .java-version located in a parent directory because jm searches directory by directory.
• The suffix mapping expresses a distribution and Java version requirement; it does not guarantee the exact same archive or build identity that SDKMAN used.
• Missing matches are not installed automatically. Run jm install explicitly.