Installing Java

Java は、 多くのプラットフォームでプログラムを実行できる人気あるプログラミング言語です。Fedora でも実行できます。もし Java プログラムを作成する場合には、 JDK (Java Development Kit) をインストールする必要があります。 Java プログラムを実行する場合は、 JRE (Java Runtime Environment) で提供される JVM (Java Virtual Machine) で実行できます。 分からない場合、 JDK をインストールしてください。なぜなら、Java プログラムを作成する意図の無い場合でも必要になることも時々あるからです。

Many flavors of Java exist and also many versions of each flavor. If you want to just run a specific application, check the documentation of that software to see what versions of Java are supported or have been tested. Most Java applications run on one of the following:

  • OpenJDK — Java Platformのオープンソースな実装であり、標準的なエディションです。 このバージョンが推奨され、Fedora ではインクルードされます。

  • Oracle Java SE — a free JDK from Oracle. This version is not open-source and we recommend that it only be used if OpenJDK is not sufficient.

You can find the following Versions:

  • Version (Ex. 8)

  • Long Term Support or LTS

  • Latest

Installing OpenJDK

Fedora リポジトリから OpenJDK をインストールするには:

  • 利用可能なバージョンのリストのために次のコマンドを実行します:

dnf search openjdk
  • インストールしたい OpenJDK のバージョンをコピーします。

OpenJDK のための色々なフレーバーが利用可能です。これらのオプションについての情報は、 OpenJDK web site を検索してください。
  • 次のコマンドを実行すれば、OpenJDK がインストールされます。

sudo dnf install <openjdk-package-name>


sudo dnf install java-1.8.0-openjdk.x86_64
sudo dnf install java-11-openjdk.x86_64
sudo dnf install java-latest-openjdk.x86_64

Installing OpenJDK for development

Java Development Kit、ランタイム環境、および関連する開発ツールをインストールする用途のため。

sudo dnf install <openjdk-package-name>-devel


sudo dnf install java-1.8.0-openjdk-devel.x86_64
sudo dnf install java-11-openjdk-devel.x86_64
sudo dnf install java-latest-openjdk-devel.x86_64

Installing Oracle Java SE

This page discusses third-party software sources not officially affiliated with or endorsed by the Fedora Project. Use them at your own discretion. Fedora recommends the use of free and open source software and avoidance of software encumbered by patents.

To install Oracle Java SE:

  1. Navigate to Oracle Java SE downloads page, and choose the version of Java you wish to use.

  2. Accept the license agreement and download the appropriate tar.gz file for your systems architecture.

  3. Unpack the tar.gz file somewhere. For example, to extract it to the /opt directory: sudo tar xf Downloads/jdk-18_linux-x64_bin.tar.gz -C /opt

  4. Set the JAVA_HOME environment variable to that directory. For example: export JAVA_HOME=/opt/jdk-

Note: Always make sure to download latest version available.

Java バージョン間の切り替え

システムに複数のバージョンの Java をインストールなされているかもしれませんが、1つから切り替えることができます。

このコマンドを実行すると、インストールされている全部の Java バージョンの全リストが表示されるので、選択します:

sudo alternatives --config java

選択番号を入力するだけで、標準で使用する Java を決められます。

  • 検証:

java -version

JDK reference

Java 関連の略語については下記のリストを参照してください:


Java Runtime Environment; required to run Java code and applications


Java Virtual Machine; main component of the JRE


Java Development Kit; required only for development, coding


Software Development Kit; see JDK


Java Web Start is a framework to start application from the Internet


JavaFX is a platform to create and deliver desktop and Rich Internet Apps


is the JavaFX Open Source implementation


Open Source project behind the Java Platform


is a support project for OpenJDK (concern only developers)


is the Java Web Start package (contains only JavaWS, no applets anymore); install to run JNPL files


時代遅れの技術です; 最近のパッケージには実装されていないです

JSE, J2SE, JEE, …​

obsolete acronyms for Java Standard & Enterprise Edition; JavaSE is like JRE

JDK components

The JDK has as its primary components a collection of programming tools, including:


this tool can be used to run and debug Java applets without a web browser


the annotation-processing tool


a utility which can detect JAR-file conflicts


the IDL-to-Java compiler. This utility generates Java bindings from a given Java IDL file.


the Java Access Bridge. Exposes assistive technologies on Microsoft Windows systems.


the loader for Java applications. This tool is an interpreter and can interpret the class files generated by the javac compiler. Now a single launcher is used for both development and deployment. The old deployment launcher, jre, no longer comes with Sun JDK, and instead it has been replaced by this new java loader.


the Java compiler, which converts source code into Java bytecode


the documentation generator, which automatically generates documentation from source code comments


the archiver, which packages related class libraries into a single JAR file. This tool also helps manage JAR files.


tool to package and sign JavaFX applications


the jar signing and verification tool


the C header and stub generator, used to write native methods


the class file disassembler


the Java Web Start launcher for JNLP applications


Java Monitoring and Management Console


the debugger


Java Heap Analysis Tool (experimental)


This utility gets configuration information from a running Java process or crash dump. (experimental)


This utility outputs the memory map for Java and can print shared object memory maps or heap memory details of a given process or core dump. (experimental)


Java Mission Control


Java Virtual Machine Process Status Tool lists the instrumented HotSpot Java Virtual Machines (JVMs) on the target system. (experimental)


Java command-line script shell.


utility which prints Java stack traces of Java threads (experimental)


Java Virtual Machine statistics monitoring tool (experimental)


jstat daemon (experimental)


tool for manipulating the keystore


JAR compression tool


the policy creation and management tool, which can determine policy for a Java runtime, specifying which permissions are available for code from various sources


visual tool integrating several command-line JDK tools and lightweight clarification needed] performance and memory profiling capabilities


generates portable JAX-WS artifacts for invoking a web service.


Part of the Java API for XML Binding (JAXB) API. It accepts an XML schema and generates Java classes.

The JDK also comes with a complete Java Runtime Environment, usually called a private runtime, due to the fact that it is separated from the "regular" JRE and has extra contents. It consists of a Java Virtual Machine and all of the class libraries present in the production environment, as well as additional libraries only useful to developers, such as the internationalization libraries and the IDL libraries.

Additional resources

For Java in Fedora, see:

For more information about Java in general, see:

To develop Java applications, consider the following open-source IDEs: