How to choose the default Java version in Arch Linux

Several versions of the JDK and OpenJDK are available in the standard Arch Linux repositories (and derivative distributions). You can install one or more of them. Even if you have the latest version installed, some programs may install a different version of the JDK as their dependency - multiple versions are allowed, they do not cause conflicts.

After that, you can see which of these versions is used by default, and also change it using the archlinux-java program.

Usage:

archlinux-java <COMMAND>

As a COMMAND it can be:

	status		List installed Java environments and enabled one
	get		Return the short name of the Java environment set as default
	set <JAVA_ENV>	Force <JAVA_ENV> as default
	unset		Unset current default Java environment
	fix		Fix an invalid/broken default Java environment configuration

Start by viewing the status:

archlinux-java status

As you can see, I have two Java environments available

• java-11-openjdk
• java-14-openjdk

And no Java environment is selected as the default.

I set java-14-openjdk as my default environment:

sudo archlinux-java set java-14-openjdk

I check again:

archlinux-java status

As you can see, java-14-openjdk is now used - the word (default) indicates this.

Errors: command java, javac or javap not found

When trying to start one of the following programs, you may encounter errors:

java
bash: java: command not found
# OR
bash: /usr/bin/java: No such file or directory

javac
bash: javac: command not found
# OR
bash: /usr/bin/javac: No such file or directory

javap
bash: javap: command not found
# OR
bash: /usr/bin/javap: No such file or directory

If you have already installed the JDK, then you need to select the version that will be used by default. This can be done using archlinux-java as shown above. After that, the error will disappear.