Installation

What is available

Java Virtual Machine (JVM)
- A runtime component.
- It is an interpreter which runs Java code.
Java Runtime Environment (JRE)
- Installed by developers and end-users.
- To run Java applications.
- Includes the JVM.
Java Development Kit (JDK)
- Development toolkit.
- Installed by developers.
- Includes the JRE.

Download

Download page on the website for the runtime.

Install with Package manager

Install with SDKMan!

Install SDKMAN!
Install Java. e.g.
```
 $ sdk install java 17.0.1-open
```

Install on Linux with APT

Find available packages:

$ sudo apt search openjdk | less
default-jdk
  Standard Java development kit

default-jre
  Standard Java runtime

openjdk-11-jdk
  OpenJDK development kit (JDK)

[...]

Install one. e.g.

$ sudo apt install default-jre

Install on macOS with Homebrew

OpenJDK

openjdk - also available under java alias. Uses OpenJDK.

$ brew install openjdk

A message I got:

...

For the system Java wrappers to find this JDK, symlink it with
  sudo ln -sfn /usr/local/opt/openjdk/libexec/openjdk.jdk /Library/Java/JavaVirtualMachines/openjdk.jdk

openjdk is keg-only, which means it was not symlinked into /usr/local,
because macOS provides similar software and installing this software in
parallel can cause all kinds of trouble.

If you need to have openjdk first in your PATH, run:
  echo 'export PATH="/usr/local/opt/openjdk/bin:$PATH"' >> ~/.zshrc

For compilers to find openjdk you may need to set:
  export CPPFLAGS="-I/usr/local/opt/openjdk/include"

Eclipse IDE for Java developers

$ brew install --cask eclipse-java

REPL

$ brew install javarepl