cjdk

cjdk (for "cached JDK") is a Python package and command-line tool to download and run JDK (Java Development Kit) or JRE (Java Runtime Environment) distributions.

Previously used JDKs are kept in the user's cache directory, so that future invocations do not require a download.

What for

• Installing exact JDK versions for reproducible testing
• Working with multiple versions of JDKs
• Deploying tools that require Java

Using the command-line interface of cjdk, you can run Java programs using a one-liner, without having to worry about whether the user has installed a new enough Java runtime and set JAVA_HOME and PATH to appropriate values.

For example, the following command will run Checkstyle using Temurin JRE 17 (which will be downloaded if this is the first time it is requested):

cjdk --jdk=temurin-jre:11 exec java -jar checkstyle-10.3-all.jar -c style.xml MyApp.java

See the documentation for detailed usage.

cjdk was inspired by Coursier's java command, and uses Coursier's JDK index). Unlike Coursier, cjdk does not require a Java runtime to bootstrap.

Installing

cjdk requires Python 3.10.

pip install cjdk

Documentation

Licensing

cjdk is distributed under the MIT license. Please see LICENSE.txt.