J'Lo – the Java Loader

The Java Loader (or J'Lo for short) is a minimalistic tool to download and manage Java installations on your machine. It is written in Rust, with a main focus on simplicity and ease of use.

J'Lo currently supports Linux (x86_64) and macOS (arm64).

At the moment, only the Eclipse Temurin distribution is available. Java versions are supported starting from Java 8, with all newer versions working automatically.

Installing J'Lo

To install J'Lo on Unix-like systems (Linux, macOS, WSL, etc.):

/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/java-loader/jlo/refs/heads/main/install.sh)"

This will download the latest J'Lo binary and install it to ~/.jlo/. You can safely re-run this command to update J'Lo to the latest version, which is basically the same as running jlo selfupdate.

Important

Watch the output closely, as you will have to add some lines to your shell profile to make jlo available in your terminal.

Quick Start

Setup environment for Java 25 (installing it first, if necessary):

# Update JAVA_HOME and PATH for Java 25 in the current shell session.
jlo env 25

# Optionally, verify that the correct Java version is being used:
echo $JAVA_HOME
which java

Alternatively:

cd /path/to/your/project

# One-time setup: create a .jlorc file that pins Java 25 for this project.
jlo init 25

# Setup JAVA_HOME and PATH for the Java version specified in the .jlorc file.
jlo env

Tip

If you enabled the J'Lo autoload feature during installation, J'Lo will automatically set up the Java environment whenever you cd into a directory that contains a .jlorc file.

JDKs are installed to ~/.jdks/ on Linux and ~/Library/Java/JavaVirtualMachines/ on macOS. This allows automatic discovery of installed JDKs by IDEs like IntelliJ IDEA.

Command Reference

Command	Description
jlo env	Set up the environment for the Java version specified in the .jlorc file.
jlo env 25	Set up the environment for the Java version given as an argument. Ignore .jlorc file.
jlo init	Create a .jlorc file that pins the latest available Java version.
jlo init 25	Create a .jlorc file that pins the given Java version. Ignore .jlorc file.
jlo update	Update the Java version from the .jlorc file to the latest minor release.
jlo update 25	Update the specified Java version to the latest minor version. Ignore .jlorc file. Multiple versions can be specified, e.g. jlo update 8 11 17. Missing versions will be installed.
jlo update all	Update all installed Java versions to their latest minor releases. Ignore .jlorc file.
jlo clean	Keep only the latest minor version of each installed major version, remove all others.
jlo selfupdate	Update J'Lo itself to the latest version.
jlo version	Print the currently installed J'Lo version.

Uninstalling J'Lo

To uninstall J'Lo, simply remove the ~/.jlo/ directory and the lines you added to your shell profile during installation.

You may also want to remove the ~/.jdks/ directory (or ~/Library/Java/JavaVirtualMachines/ on macOS) if you no longer need the installed JDKs.