jEnv - Java Version Manager

jEnv is a command-line tool that helps you manage multiple Java versions easily.
jEnv is a command line tool to help you forget how to set the JAVA_HOME environment variable

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1. Install jEnv

brew install jenv

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2. Configure your shell

Add jEnv to your shell environment:

Bash

echo 'export PATH="$HOME/.jenv/bin:$PATH"' >> ~/.bash_profile
echo 'eval "$(jenv init -)"' >> ~/.bash_profile
source ~/.bash_profile # Reload the shell

Zsh

echo 'export PATH="$HOME/.jenv/bin:$PATH"' >> ~/.zshrc
echo 'eval "$(jenv init -)"' >> ~/.zshrc
source ~/.zshrc # Reload the shell

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3. Enable the export plugin

Enable plugins to automatically set JAVA_HOME and integrate with Maven:

eval "$(jenv init -)"
jenv enable-plugin export
jenv enable-plugin maven

Restart your shell:

exec $SHELL -l

4. Add JDKs/JREs

Make sure the paths match the JDKs you have installed.

jenv add /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home
jenv add /Library/Java/JavaVirtualMachines/jdk17011.jdk/Contents/Home
jenv add /Library/Java/JavaVirtualMachines/jdk1.8.0.jdk/Contents/Home 
jenv add /Library/Java/JavaVirtualMachines/jdk-21.jdk/Contents/Home

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5. List managed JDKs

$ jenv versions
  system
  oracle64-1.6.0.39
* oracle64-1.7.0.11 (set by /Users/hikage/.jenv/version)

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6. Configure global version

jenv global oracle64-1.6.0.39

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7. Configure local version (per directory)

jenv local oracle64-1.6.0.39

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8. Configure shell instance version

jenv shell oracle64-1.6.0.39

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9. Verify

Verify the current jenv version:

jenv version

Example output:

21.0 (set by /Users/youruser/.jenv/version)

Verify the current Java version:

java -version

Example output:

java version "21.0.4" 2024-07-16 LTS
Java(TM) SE Runtime Environment (build 21.0.4+8-LTS-274)
Java HotSpot(TM) 64-Bit Server VM (build 21.0.4+8-LTS-274, mixed mode, sharing)

Verify the java version on maven:

mvn -version

Example output:

Apache Maven 3.9.6
Java version: 21.0.4, vendor: Oracle Corporation

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Troubleshooting

Problem:

/Users/username/.jenv/shims/java: line 21: /usr/local/Cellar/jenv/0.5.6/libexec/libexec/jenv: No such file or directory

Solution:
Refer to the GitHub issue #394:

jenv --version
jenv rehash

If .jenv-shim exists and causes errors, rename it, then run:

jenv rehash

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References

For more details, check the official website: https://www.jenv.be