The Java JDK (Java Development Kit) is a software development environment used for developing Java Applications. It is a collection of programming tools, notably JRE (Java Runtime Environment), Java (Loader for Java Application), Javac (Compiler), Jar (Archiver), etc.
Java JRE (Java Runtime Environment) contains tools for running Java applications.
OpenJDK is an open-source implementation of the Oracle Java SE platform edition, and there is no technical difference between OpenJDK and Oracle JDK.
Here, we will see how to install Java JDK/JRE 17/11/8 on Fedora 35.
Install Java on Fedora 35
You can install OpenJDK or Oracle Java as per your requirement. You can also have multiple versions of Java (OpenJDK and Oracle Java) on your system.
Install OpenJDK
Installing OpenJDK is a pretty straightforward process in Fedora. You can use the dnf command to install OpenJDK.
Install OpenJDK JDK
# Java JDK 17 sudo dnf install -y java-17-openjdk-devel # Java JDK 11 sudo dnf install -y java-11-openjdk-devel # Java JDK 8 sudo dnf install -y java-1.8.0-openjdk-devel
Install OpenJDK JRE
# Java JRE 17 sudo dnf install -y java-17-openjdk # Java JRE 11 sudo dnf install -y java-11-openjdk # Java JRE 8 sudo dnf install -y java-1.8.0-openjdk
Install Oracle Java
There is no separate JRE (Java Runtime Environment) anymore. Instead, Oracle JDK now provides JRE as well.
Download Oracle Java JDK
You can either use the command line or browser to download the JDK.
Go to the Oracle JDK page to download packages using the browser. Then, download the rpm binary package for easy installation.
Oracle Java JDK 17 (LTS):
Download Oracle Java 17 (v17.0.1)
Oracle Java JDK 11 (LTS):
Download Oracle Java 11 (v11.0.13) (Login Required)
Oracle Java JDK 8:
Download Oracle Java 8 (v8u311) (Login Required)
If you still want to download through the command line, install the wget package.
sudo dnf install -y wget
Then, use the below command to download Oracle Java using the terminal.
# Oracle Java JDK 17 wget https://download.oracle.com/java/17/latest/jdk-17_linux-x64_bin.rpm # Oracle Java JDK 11 # Oracle Java JDK 8
Install Oracle Java JDK
After downloading the package, install Oracle Java JDK using the rpm command.
# Oracle Java JDK 17 sudo rpm -ivh jdk-17_linux-x64_bin.rpm # Oracle Java JDK 11 sudo rpm -ivh jdk-11.0.13_linux-x64_bin.rpm # Oracle Java JDK 8 sudo rpm -ivh jdk-8u311-linux-x64.rpm
By default, Java JDK is installed in /usr/java/ directory. To install Oracle JDK to a custom directory, use rpm -ivh –prefix=// rpmfile command.
Set Default Java Version
Use the alternatives command to set the default java version.
sudo alternatives --config java
Select Java:
If your system has multiple Java versions, the above command will list all Java versions like below.
There are 3 programs which provide 'java'. Selection Command ----------------------------------------------- + 1 java-11-openjdk.x86_64 (/usr/lib/jvm/java-11-openjdk-11.0.12.0.7-4.fc35.x86_64/bin/java) 2 java-latest-openjdk.x86_64 (/usr/lib/jvm/java-17-openjdk-17.0.1.0.12-2.rolling.fc35.x86_64/bin/java) * 3 /usr/java/jdk-17.0.1/bin/java Enter to keep the current selection[+], or type selection number: 3
Enter the number below the selection column to set the default Java version.
Here, I chose 3 for Oracle Java 17.
Verify Java Version
Check the java version using the following command.
java -version
Output:
java version "17.0.1" 2021-10-19 LTS Java(TM) SE Runtime Environment (build 17.0.1+12-LTS-39) Java HotSpot(TM) 64-Bit Server VM (build 17.0.1+12-LTS-39, mixed mode, sharing)
The output may vary depending upon the package and the version you chose to be the default Java version.
Setup Environmental Variables
Java applications often require JAVA environment variables to be set in the system. To set JAVA variables at the system level, create a file in the /etc/profile.d directory.
vi /etc/profile.d/java.sh
Then, add the required variables.
To set the environment variables for a particular user, place the below variables in the .bash_profile file in the home directory.
export PATH=$PATH:/usr/java/jdk-17.0.1/bin/ export JAVA_HOME=/usr/java/jdk-17.0.1/
Finally, load the environments into the current session.
source /etc/profile.d/java.sh
Sumber: disini