Installing (multiple) Java on MacOS managed by jEnv

Jimmy Tang — Mon, 07 Oct 2024 06:45:22 +0000

Install some Java!

I'm gonna install three version's from openjdk using Homebrew! We should all know what Homebrew is by now...
$ brew install openjdk@17
$ brew install openjdk@21

Create some Symlinks

As far as I understand it MacOS has a special Java VM folder where it installs the JVMs. We'll create symlinks to versions we just installed from Homebrew.
sudo ln -sfn /opt/homebrew/opt/openjdk@17/libexec/openjdk.jdk /Library/Java/JavaVirtualMachines/openjdk-17.jdk
sudo ln -sfn /opt/homebrew/opt/openjdk@21/libexec/openjdk.jdk /Library/Java/JavaVirtualMachines/openjdk-21.jdk

Install jEnv

jenv is a Java installation version manager. Install with Homebrew as well:
$ brew install jenv

Add the following to your shell's .rc file so jenv is executed upon terminal startup

# Setup JEnv to install run
export PATH="$HOME/.jenv/bin:$PATH"
eval "$(jenv init -)"
# Have JAVA_HOME set by JEnv for us...
jenv enable-plugin export

Source the file to apply the changes
source ~/.zshrc # or ~/.bash_profile, ~/.bashrc, etc.

Add the JVMs to jenv

Add the versions in Java VM folder to jenv so it can manage them
jenv add /Library/Java/JavaVirtualMachines/openjdk-17.jdk/Contents/Home/
jenv add /Library/Java/JavaVirtualMachines/openjdk-21.jdk/Contents/Home/

See the versions installed by jenv

You can see the installed versions by echo ${JAVA_HOME}

$ jenv versions
* system (set by /Users/user/.jenv/version)
  17
  17.0
  17.0.12
  21
  21.0
  21.0.4
  openjdk64-17.0.12
  openjdk64-21.0.4

See which version of Java you're using:

$ java -version
openjdk version "17.0.12" 2024-07-16
OpenJDK Runtime Environment Homebrew (build 17.0.12+0)
OpenJDK 64-Bit Server VM Homebrew (build 17.0.12+0, mixed mode, sharing)

Set/unset global version of Java

$ jenv global 21.0.2
$ jenv global --unset

Set/unset local version of Java

This will add a .java-version file in the directory you're currently in so you can commit it as a part of your Java project.

$ jenv local 21.0.2
$ jenv local --unset

Congrats! You've just installed Java on your MacOS! Have fun on your Java/Kotlin projects! 🥳

Enabling ESLint on Intellij & VSCode

Jimmy Tang — Fri, 26 Feb 2021 16:03:02 +0000

ESLint is a pretty cool tool that cleans up your Javascript code for you! But when you're deving on an IDE such as IntelliJ/WebStorm/VSCode, who wants to be running npm run lint all the time am I right?

"Would be pretty awesome to have my IDE run my linting automatically... But how?" - You.

You've come to the right place my friend! 🎉

IntellJ/WebStorm

Let's start with IntelliJ first because it's the easiest! It's usually already set up on IntelliJ (and subsequently WebStorm). In case it isn't, here are the steps to enable it.

I'm assuming you already have a .eslintrc.* file in your project root directory. This is usually standard practice. If not, make one and put all your settings in there!

For context, the project I'll be using in this example is a Vue project.

Find your Settings (where this is differs for Windows/OSX)
Forgive me for I am but a Windows pleb
Go to Language & Frameworks > Javascript > Code Quality Tools > ESLint
Ensure this option is checked
Make sure that the "Automatic ESLint configuration" is checked! Like the screenshot says, it will use the ESLint package as well as the .eslintrc.* to run the linter.
Fix your mistakes, noobs
Now, in the files that you work on, the IDE will pick up any mistakes you made and highlight them for you to fix up! Easy!

VSCode

VSCode is a little trickier to set up as it doesn't come with a tool to run ESLint out of a box. You have to install it as an extension.

The most popular ESLint extention by far is ESLint by Dirk Baeumer.

Can't go wrong when it's been installed over 13 million times

Once it is installed, make sure it is enabled (by clicking on the Enable button if it isn't already), and just like the setup for IntelliJ, check that your .eslintrc.* file is in your project root!

Open the Command Palette
...Or you can hit Ctrl + Shift + P
Search for this Command: "ESLint: Manage Library Execution"
Allowing ESLint Extension to run in your project
A popup like below should show up asking if you want to allow the ESLint extension to run the ESLint you've installed in your project using the .eslintrc.* config file. This is different to clicking the 'Enable' button after you install the ESLint Extension so make sure you don't skip this step! As for which option you should pick. Allow Everywhere enables ESLint for all workspaces (or projects) which is useful if all your project happen to be Javascript based. Otherwise Allow will just enable it for this project and you have to repeat these steps for all subsequent projects.
Allow... Everywhere? 🤔
Now just open up your Javascript files and start fixing up any mistakes the linter picks up!
ESLint: "REEEEEEEEEEEEEeeeee..."

Linting `.vue` files!

If you're linting .vue files like I am, the ESLint extension doesn't pick up Vue SFC files. If your project is pure Javascript or React, you don't need to worry about this extra step!

According to the official eslint-plugin-vue guide here, we need to create a .vscode folder in the root directory of the project and within it, create a settings.json file.

Inside that file, you'll need to add a bit of extra config for the ESLint plugin to pick up .vue files.



{
  "eslint.validate": [
    "javascript",
    "javascriptreact",
    "vue"
  ],
  "vetur.validation.template": false
}

The vetur setting is if you have the vetur plugin installed.

And that's it! Happy Linting!

DEV Community: Jimmy Tang