Managing Multiple Java Installations
Learn more about managing Java installation.
Join the DZone community and get the full member experience.Join For Free
With more and more Java releases coming up, it’ll be more interesting to manage multiple Java installations on your local environment. Different projects may require different Java versions.
You may also like: How to Install Multiple Versions of Java on the Same Machine
The jenv project is a convenient way how to manage Java installations. It can set up local Java installations on a global, directory, and shell level and uses easy-to-remember Java version identifiers:
$> jenv versions 11 12.0 13.0 1.8 * 126.96.36.199 9.0 9.0.4 openj9-jdk-12.0.1 openj9-jdk-13.0.1 openjdk64-11.0.2 openjdk64-12.0.1 openjdk64-13.0.1 oracle64-188.8.131.52 oracle64-9.0.4 # switch to JDK 13 globally $> jenv global 13.0 # switch to JDK 9 locally $> cd project/ $> jenv local 9.0 $> java -version java version "9.0.4" Java(TM) SE Runtime Environment (build 9.0.4+11) Java HotSpot(TM) 64-Bit Server VM (build 9.0.4+11, mixed mode) $> cd .. && java -version openjdk version "13.0.1" 2019-10-15 OpenJDK Runtime Environment AdoptOpenJDK (build 13.0.1+9) Eclipse OpenJ9 VM AdoptOpenJDK (build openj9-0.17.0, ...)
Jenv stores the local Java version in a
Jenvs works by declaring wrapper
java binaries that direct to the corresponding installation based on the context.
Shell scripts can also set a specific version via the
JENV_VERSION environment variable:
#!/bin/bash JENV_VERSION='13.0' # will use JDK 13 java -version
Some of the content of this post was reposted from my newsletter issue 025.
Published at DZone with permission of Sebastian Daschner. See the original article here.
Opinions expressed by DZone contributors are their own.