# jir

[github](https://github.com/rururunu/Jir)

`jir` helps you manage Java versions without fighting `JAVA_HOME`.

Install a JDK, switch to it, and keep your active Java runtime behind one stable path: `home/occupy`.

## Why

If you often switch between Java 8, 17, 21, or different vendors like Temurin, Corretto, Zulu, Oracle, and Microsoft OpenJDK, `jir` keeps that workflow simple.

You can set `JAVA_HOME` to `home/occupy` once. After that, `jir use 21:temurin` switches Java without editing environment variables again.

On Windows, switching uses a directory junction, so it is fast and does not copy the whole JDK.

## Install

Download or build the Windows GUI installer:

```text
dist/jir-0.1.0-windows-x64-gui-setup.exe

The installer lets you choose where jir lives. It can also add jir to PATH and set JAVA_HOME for you.

After installing, open a new terminal and check:

jir -h

Quick Start

See what you can install:

jir ls -i

Install Java 21. If there are multiple vendors, jir will let you choose one:

jir i 21

Already know what you want?

jir i 21:temurin

Switch to it:

jir use 21:temurin

Check what is active:

jir current

Remove something you no longer need:

jir uni 21:temurin

Commands

• jir, jir -h, jir -help, jir --help: show help.
• jir ls: show installed JDKs.
• jir ls -i: show installable JDKs.
• jir i 21: install Java 21 and choose a vendor.
• jir i 21:temurin: install a specific distro.
• jir use 21: choose an installed Java 21 distro and activate it.
• jir use 21:temurin: activate a specific installed distro.
• jir current: show the active Java runtime.
• jir uni 21:temurin: uninstall a JDK after confirmation.