Java

From the Wikipedia article:

Java is a programming language originally developed by Sun Microsystems and released in 1995 as a core component of Sun Microsystems' Java platform. The language derives much of its syntax from C and C++ but has a simpler object model and fewer low-level facilities. Java applications are typically compiled to bytecode that can run on any Java virtual machine (JVM) regardless of computer architecture.

Arch Linux officially supports the open source OpenJDK versions 8, 11, 17 and 18. All these JVM can be installed without conflict and switched between using helper script archlinux-java. Several other Java environments are available in AUR but are not officially supported.

Installation

Note:

Arch Linux officially only supports the OpenJDK implementation.
After installation, the Java environment will need to be recognized by the shell ($PATH variable). This can be done by sourcing /etc/profile from the command line or by logging out/in again of the Desktop Environment or reboot.

Two common packages are respectively pulled as dependency, named java-runtime-common (containing common files for Java Runtime Environments) and java-environment-common (containing common files for Java Development Kits). The provided environment file /etc/profile.d/jre.sh points to a linked location /usr/lib/jvm/default/bin, set by the archlinux-java helper script.

Warning: The links /usr/lib/jvm/default and /usr/lib/jvm/default-runtime should always be edited with archlinux-java.

This is used to display and point to a working default Java environment in /usr/lib/jvm/java-${JAVA_MAJOR_VERSION}-${VENDOR_NAME} or a Java runtime in /usr/lib/jvm/java-${JAVA_MAJOR_VERSION}-${VENDOR_NAME}/jre.

Most executables of the Java installation are provided by direct links in /usr/bin, while others are available in $PATH. The script /etc/profile.d/jdk.sh is no longer provided by any package.

OpenJDK

OpenJDK is an open-source implementation of the Java Platform, Standard Edition (Java SE), designated as the official reference implementation. There are several distributors of OpenJDK builds such as Adoptium (formerly known as AdoptOpenJDK) and Amazon Corretto. The Arch Linux OpenJDK packages are built from the upstream OpenJDK source code.

Headless JRE: The minimal Java runtime - needed for executing non-GUI Java programs.
Full JRE: Full Java runtime environment - needed for executing Java GUI programs, depends on headless JRE.
JDK: Java Development Kit - needed for Java development, depends on full JRE.

Version	Headless JRE	Full JRE	JDK	Documentation	Sources
OpenJDK 18	jre-openjdk-headless	jre-openjdk	jdk-openjdk	openjdk-doc	openjdk-src
OpenJDK 17	jre17-openjdk-headless	jre17-openjdk	jdk17-openjdk	openjdk17-doc	openjdk17-src
OpenJDK 11	jre11-openjdk-headless	jre11-openjdk	jdk11-openjdk	openjdk11-doc	openjdk11-src
OpenJDK 8	jre8-openjdk-headless	jre8-openjdk	jdk8-openjdk	openjdk8-doc	openjdk8-src

OpenJDK GA — Latest OpenJDK General-Availability Release build from Oracle.

https://jdk.java.net || java-openjdk-bin^AUR

OpenJDK EA — Latest OpenJDK Early-Access build for development version from Oracle.

https://jdk.java.net || java-openjdk-ea-bin^AUR

IcedTea-Web — Java Web Start and the deprecated Java browser plugin.

https://icedtea.classpath.org/download/icedtea-web-docs/1.8/html/en/icedtea-web.html || icedtea-web

OpenJFX

OpenJFX is the open-source implementation of JavaFX. You do not need to install this package if you are using Oracle JDK. This package only concerns users of the open source implementation of Java (OpenJDK project), and its derivatives.

Version	Runtime and Developement	Documentation	Sources
OpenJFX 18	java-openjfx	java-openjfx-doc	java-openjfx-src
OpenJFX 17	java17-openjfx	java17-openjfx-doc	java17-openjfx-src
OpenJFX 11	java11-openjfx	java11-openjfx-doc	java11-openjfx-src
OpenJFX 8	java8-openjfx^AUR	java8-openjfx-doc^AUR	java8-openjfx-src^AUR

OpenJFX GA — Latest OpenJFX General-Availability Release build from Gluon.

https://openjfx.io/ || java-openjfx-bin^AUR

OpenJFX EA — Latest OpenJFX Early-Access build for development version from Gluon.

https://openjfx.io/ || java-openjfx-ea-bin^AUR

Other implementations

Oracle JDK — Oracle's commercially licensed build of OpenJDK.

https://www.oracle.com/technetwork/java/javase/downloads/index.html || jre^AUR jre12^AUR jre11^AUR jre10^AUR jre9^AUR jre8^AUR jre7^AUR jre6^AUR jdk^AUR jdk12^AUR jdk11^AUR jdk10^AUR jdk9^AUR jdk8^AUR jdk7^AUR jdk6^AUR jdk-devel^AUR

OpenJ9 — Eclipse's implementation of JRE, contributed by IBM.

https://www.eclipse.org/openj9/ || jdk-openj9-bin^AUR jdk14-openj9-bin^AUR jdk13-openj9-bin^AUR jdk12-openj9-bin^AUR jdk11-openj9-bin^AUR jdk10-openj9-bin^AUR jdk9-openj9-bin^AUR jdk8-openj9-bin^AUR

IBM Certified — IBM Semeru Runtime Certified Edition.

https://www.ibm.com/semeru-runtimes/downloads || jdk11-j9-bin^AUR

IBM J9 — IBM's implementation of JRE, using OpenJ9 contributions.

https://www.ibm.com/support/pages/java-sdk-downloads || jdk8-j9-bin^AUR jdk7-j9-bin^AUR jdk7r1-j9-bin^AUR

Parrot VM — a VM with experimental support for Java [1] through two different methods: either as a Java VM bytecode translator, or as a Java compiler targeting the Parrot VM. Parrot is not actively developed since 2017.

http://www.parrot.org/ || parrot^AUR

Note: 32-bit versions of Oracle JDK can be found by prefixing bin32-, e.g. bin32-jre^AUR. They use java32-runtime-common^AUR, which functions as java-runtime-common by suffixing with 32, e.g. java32. The same analogy applies to java32-environment-common^AUR, which is only used by 32-bit JDK packages.

Development tools

For integrated development environments, see List of applications#Integrated development environments and the Java IDEs subsection specifically.

To discourage reverse engineering an obfuscator like proguard^AUR can be used.

Decompilers

CFR — Java decompiler, supporting modern features of Java 9, 10 and beyond.

https://www.benf.org/other/cfr/ || cfr^AUR

Fernflower — Analytical decompiler for Java, developed as part of IntelliJ IDEA.

https://github.com/JetBrains/intellij-community/tree/master/plugins/java-decompiler/engine || fernflower-git^AUR

Krakatau — Java decompiler, assembler, and disassembler.

https://github.com/Storyyeller/Krakatau || krakatau-git^AUR

Procyon decompiler — Experimental Java decompiler, inspired by ILSpy and Mono.Cecil.

https://bitbucket.org/mstrobel/procyon/wiki/Java%20Decompiler || procyon-decompiler^AUR

Java Decompiler (JD-Core) — Popular Java decompiler providing a GUI (see JD-GUI) and supporting Java 1-10.

https://java-decompiler.github.io/ || jd-core-java^AUR

Jadx — Android DEX to Java decompiler with an optional GUI (see Jadx-GUI)

https://github.com/skylot/jadx || jadx

JAD — Unmaintained Java decompiler (last release 2006).

https://varaneckas.com/jad || jad

GUI Frontends

Bytecode Viewer — Java reverse engineering suite, including a decompiler, editor and debugger; Frontend for CFR/Fernflower/Procyon

https://bytecodeviewer.com || bytecode-viewer^AUR

Recaf — An easy to use modern Java bytecode editor that abstracts away the complexities of Java programs; Frontend for CFR/Fernflower/Procyon

https://www.coley.software/Recaf/ || recaf-bin^AUR

Java Decompiler (JD-GUI) — Popular Java decompiler providing a GUI and supporting Java 1-10; Frontend for JD-Core

https://java-decompiler.github.io/ || jd-gui^AUR

Jadx-GUI — Android APK DEX to Java decompiler with an optional GUI; Frontend for Jadx

https://github.com/skylot/jadx || jadx

Luyten — An Open Source Java Decompiler Gui; Frontend for Procyon

https://github.com/deathmarine/Luyten || luyten^AUR

Switching between JVM

The helper script archlinux-java provides such functionalities:

archlinux-java <COMMAND>

COMMAND:
	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

List compatible Java environments installed

$ archlinux-java status

Example:

$ archlinux-java status

Available Java environments:
   java-11-openjdk (default)
   java-8-openjdk/jre

Note the (default) denoting that java-11-openjdk is currently set as default. Invocation of java and other binaries will rely on this Java install. Also note on the previous output that only the JRE part of OpenJDK 8 is installed here.

Change default Java environment

# archlinux-java set <JAVA_ENV_NAME>

Example:

# archlinux-java set java-8-openjdk/jre

Tip: To see possible <JAVA_ENV_NAME> names, use archlinux-java status.

Note that archlinux-java will not let you set an invalid Java environment. In the previous example, jre8-openjdk is installed but jdk8-openjdk is not so trying to set java-8-openjdk will fail:

# archlinux-java set java-8-openjdk

'/usr/lib/jvm/java-8-openjdk' is not a valid Java environment path

Unsetting the default Java environment

There should be no need to unset a Java environment as packages providing them should take care of this. Still should you want to do so, just use command unset:

# archlinux-java unset

Fixing the default Java environment

If an invalid Java environment link is set, calling the archlinux-java fix command tries to fix it. Also note that if no default Java environment is set, this will look for valid ones and try to set it for you. Officially supported package "OpenJDK 8" will be considered first in this order, then other installed environments.

# archlinux-java fix

Launching an application with the non-default java version

If you want to launch an application with another version of java than the default one (for example if you have both version 18 and 11 installed on your system), you can wrap your application in a small bash script to locally change the default PATH of java. For example if the default version is java 18 and you want to use java 11:

#!/bin/sh

export PATH="/usr/lib/jvm/java-11-openjdk/bin/:$PATH"
exec /path/to/application "$@"

For a systemd service you can append JAVA_HOME to environment variables in the drop-in file:

/etc/systemd/system/unit.d/override.conf

[Service]
Environment=JAVA_HOME=/usr/lib/jvm/java-11-openjdk

Package pre-requisites to support `archlinux-java`

Note: This info also applies to archlinux32-java for 32-bit Java packages, with the proper inclusion of 32 to the package/executable names, where applicable.

This section is targeted at packager willing to provide packages in AUR for an alternate JVM and be able to integrate with Arch Linux JVM scheme to use archlinux-java. To do so, packages should:

Place all files under /usr/lib/jvm/java-${JAVA_MAJOR_VERSION}-${VENDOR_NAME}
Ensure all executables for which java-runtime-common and java-environment-common provide links are available in the corresponding package
Ship links from /usr/bin to executables, only if these links do not already belong to java-runtime-common and java-environment-common
Suffix man pages with -${VENDOR_NAME}${JAVA_MAJOR_VERSION} to prevent conflicts (see jre8-openjdk file list where man pages are suffixed with -openjdk8)
Do not declare any conflicts nor replaces with other JDKs, java-runtime, java-runtime-headless nor java-environment
Use script archlinux-java in install functions to set the Java environment as default if no other valid Java environment is already set (ie: package should not force install as default). See officially supported Java environment package sources for examples

Also please note that:

Packages that need any Java environment should declare dependency on java-runtime, java-runtime-headless or java-environment as usual
Packages that need a specific Java vendor should declare dependency on the corresponding package
OpenJDK packages now declare provides="java-runtime-openjdk=${pkgver}" etc. This enables a third-party package to declare dependency on an OpenJDK without specifying a version

Troubleshooting

MySQL

Due to the fact that the JDBC-drivers often use the port in the URL to establish a connection to the database, it is considered "remote" (i.e., MySQL does not listen to the port as per its default settings) despite the fact that they are possibly running on the same host, Thus, to use JDBC and MySQL you should enable remote access to MySQL, following the instructions in MariaDB#Grant remote access.

IntelliJ IDEA

If IntelliJ IDEA outputs The selected directory is not a valid home for JDK with the system Java SDK path, you may have to install a different JDK package and select it as IDEA's JDK.

Impersonate another window manager

You may use the wmname from suckless.org to make the JVM believe you are running a different window manager. This may solve a rendering issue of Java GUIs occurring in window managers like Awesome or Dwm or Ratpoison. Try set "compiz" or "LG3D"

$ wmname compiz

You must restart the application in question after issuing the wmname command.

This works because the JVM contains a hard-coded list of known, non-re-parenting window managers. For maximum irony, some users prefer to impersonate LG3D, the non-re-parenting window manager written by Sun, in Java.

Illegible fonts

In addition to the suggestions mentioned below in #Better font rendering, some fonts may still not be legible afterwards. If this is the case, there is a good chance Microsoft fonts are being used. Install ttf-ms-fonts^AUR.

Missing text in some applications

If some applications are completely missing texts it may help to use the options under #Tips and tricks as suggested in FS#40871.

Gray window, applications not resizing with WM, menus immediately closing

The standard Java GUI toolkit has a hard-coded list of "non-reparenting" window managers. If using one that is not on that list, there can be some problems with running some Java applications. One of the most common problems is "gray blobs", when the Java application renders as a plain gray box instead of rendering the GUI. Another one might be menus responding to your click, but closing immediately.

There are several things that may help:

See #Impersonate another window manager.
For jre8-openjdk, append the line export _JAVA_AWT_WM_NONREPARENTING=1 in /etc/profile.d/jre.sh. Then, source the file /etc/profile.d/jre.sh or log out and log back in.
For last version of JDK append line export AWT_TOOLKIT=MToolkit in ~/.xinitrc before exec window manager.
For Oracle's JRE/JDK, use SetWMName. However, its effect may be canceled when also using XMonad.Hooks.EwmhDesktops. In this case, appending >> setWMName "LG3D" to the LogHook may help.
For sway, export _JAVA_AWT_WM_NONREPARENTING=1 may solve the problem.

See [2] for more information.

System freezes when debugging JavaFX Applications

If your system freezes while debugging a JavaFX Application, you can try to supply the JVM option -Dsun.awt.disablegrab=true.

See https://bugs.java.com/bugdatabase/view_bug.do?bug_id=6714678

JavaFX's MediaPlayer constructor throws an exception

Creating instance of MediaPlayer class from JavaFX's sound modules might throw following exception (both Oracle JDK and OpenJDK)

... (i.e. FXMLLoader construction exceptions) ...
Caused by: MediaException: UNKNOWN : com.sun.media.jfxmedia.MediaException: Could not create player! : com.sun.media.jfxmedia.MediaException: Could not create player!
 at javafx.scene.media.MediaException.exceptionToMediaException(MediaException.java:146)
 at javafx.scene.media.MediaPlayer.init(MediaPlayer.java:511)
 at javafx.scene.media.MediaPlayer.<init>(MediaPlayer.java:414)
 at <constructor call>
...

which is a result of some incompatibilities of JavaFX with modern ffmpeg build delivered within Arch Linux repository.

Working solution is to install ffmpeg-compat-55^AUR.

See https://www.reddit.com/r/archlinux/comments/70o8o6/using_a_javafx_mediaplayer_in_arch/

Java applications cannot open external links

If a Java application is not able to open a link to, for example, your web browser, install gvfs. This is required by the Desktop.Action.BROWSE method. See [3]

Error initializing QuantumRenderer: no suitable pipeline found

Possible issues / solutions:

GTK2 is missing. Install gtk2
OpenJFX is missing. Install java-openjfx

Tips and tricks

Note: Suggestions in this section are applicable to all applications, using explicitly installed (external) Java runtime. Some applications are bundled with own (private) runtime or use own mechanics for GUI, font rendering, etc., so none of written below is guaranteed to work.

Behavior of most Java applications can be controlled by supplying predefined variables to Java runtime. From this forum post, a way to do it consists of adding the following line in your ~/.bash_profile (or /etc/profile.d/jre.sh to affect programs that are not run by sourcing ~/.bash_profile):

export JDK_JAVA_OPTIONS="-D<option 1> -D<option 2>..."

For example, to use system anti-aliased fonts and make swing use the GTK look and feel:

export JDK_JAVA_OPTIONS='-Dawt.useSystemAAFontSettings=on -Dswing.aatext=true -Dswing.defaultlaf=com.sun.java.swing.plaf.gtk.GTKLookAndFeel'

Three such variables exist, the options which are explained later in the table below take priority.

JAVA_TOOL_OPTIONS	Affects applications as well as tools like javac or the jshell.
JDK_JAVA_OPTIONS	Affects applications (everything started via the java command). Requires Java 9.
(command line options)	Arguments specified before the "class name" argument are Java options.
_JAVA_OPTIONS	The old way, affects applications and tools.

Better font rendering

Both closed source and open source implementations of Java are known to have improperly implemented anti-aliasing of fonts. This can be fixed with the following options: -Dawt.useSystemAAFontSettings=on, -Dswing.aatext=true

See Java Runtime Environment fonts for more detailed information.

Silence 'Picked up JDK_JAVA_OPTIONS' message on command line

Setting the JDK_JAVA_OPTIONS environment variables makes java (openjdk) write to stderr messages of the form: 'Picked up JDK_JAVA_OPTIONS=...'. To suppress those messages in your terminal you can unset the environment variable in your ~/.bashrc and alias java to pass those same options as command line arguments:

SILENT_JAVA_OPTIONS="$JDK_JAVA_OPTIONS"
unset JDK_JAVA_OPTIONS
alias java='java "$SILENT_JAVA_OPTIONS"'

Non interactive shells, like the launcher scripts for Java programs, (usually) do not read the ~/.bashrc, but still inherited exported variables from their parent process (which in turn inherited it at some point from the login shell which read the ~/.bash_profile). As for the cases when they do, one put’s generally a statement at the op of the ~/.bashrc to avoid the file being read. That way, the variables are passed to programs launched via the desktop menu and in the case of an interactive shell where the message would disturb aliases are used instead (which in turn cannot be used in scripts).

GTK LookAndFeel

If your Java programs look ugly, you may want to set up the default look and feel for the swing components:

swing.defaultlaf=com.sun.java.swing.plaf.gtk.GTKLookAndFeel

Some Java programs insist on using the cross platform Metal look and feel. In some of these cases you can force these applications to use the GTK look and feel by setting the following property:

swing.crossplatformlaf=com.sun.java.swing.plaf.gtk.GTKLookAndFeel

GTK3 Support

In Java releases prior to version 9, the GTK LookAndFeel is linked against GTK2, whilst many newer desktop applications use GTK3. This incompatibility between GTK versions may break applications utilizing Java plugins with GUI, as the mixing of GTK2 and GTK3 in the same process is not supported (for example, LibreOffice 5.0).

The GTK LookAndFeel can be run against GTK versions 2, 2.2 and 3, defaulting to GTK3. This can be overridden by setting the following property:

jdk.gtk.version=2.2

HiDPI

Depending on the GUI framework, HiDPI#Java applications can be enabled using different methods.

Better 2D performance

Switching to OpenGL-based hardware acceleration pipeline will improve 2D performance

export JDK_JAVA_OPTIONS='-Dsun.java2d.opengl=true'

Note: Enabling this option may cause the UI of software like JetBrains IDEs misbehave, making them drawing windows, popups and toolbars partially.

Java

Contents

Installation

OpenJDK

OpenJFX

Other implementations

Development tools

Decompilers

GUI Frontends

Switching between JVM

List compatible Java environments installed

Change default Java environment

Unsetting the default Java environment

Fixing the default Java environment

Launching an application with the non-default java version

Package pre-requisites to support `archlinux-java`

Troubleshooting

MySQL

IntelliJ IDEA

Impersonate another window manager

Illegible fonts

Missing text in some applications

Gray window, applications not resizing with WM, menus immediately closing

System freezes when debugging JavaFX Applications

JavaFX's MediaPlayer constructor throws an exception

Java applications cannot open external links

Error initializing QuantumRenderer: no suitable pipeline found

Tips and tricks

Better font rendering

Silence 'Picked up JDK_JAVA_OPTIONS' message on command line

GTK LookAndFeel

GTK3 Support

HiDPI

Better 2D performance

See also

Java

Installation

OpenJDK

OpenJFX

Other implementations

Development tools

Decompilers

GUI Frontends

Switching between JVM

List compatible Java environments installed

Change default Java environment

Unsetting the default Java environment

Fixing the default Java environment

Launching an application with the non-default java version

Package pre-requisites to support archlinux-java

Troubleshooting

MySQL

IntelliJ IDEA

Impersonate another window manager

Illegible fonts

Missing text in some applications

Gray window, applications not resizing with WM, menus immediately closing

System freezes when debugging JavaFX Applications

JavaFX's MediaPlayer constructor throws an exception

Java applications cannot open external links

Error initializing QuantumRenderer: no suitable pipeline found

Tips and tricks

Better font rendering

Silence 'Picked up JDK_JAVA_OPTIONS' message on command line

GTK LookAndFeel

GTK3 Support

HiDPI

Better 2D performance

See also

Package pre-requisites to support `archlinux-java`