How to Install Java on CentOS 7 and 8

How to Install Java on CentOS

OpenJDK is the open-source Java implementation packaged in the CentOS repositories, so installing it needs no third-party repo. This guide covers CentOS 7 (yum) and CentOS 8 / Stream (dnf) — the package names are identical, only the package manager differs.

Step 1: Update the package index

Refresh the repository metadata so you install the current build:

sudo yum update -y

On CentOS 8 or Stream, use dnf instead:

sudo dnf update -y

Step 2: Install the OpenJDK runtime

The runtime (JRE) is enough to run Java applications. Java 11 is the long-term support release available on CentOS:

sudo yum install java-11-openjdk -y

If your application needs Java 8, install java-1.8.0-openjdk instead. To see everything available:

yum search openjdk

Step 3: Install the development package

If you intend to compile Java rather than only run it, you also need the JDK, which provides javac:

sudo yum install java-11-openjdk-devel -y

Step 4: Confirm the packages are installed

Ask the RPM database what landed:

rpm -qa | grep openjdk

You should see both the runtime and, if you installed it, the -devel package listed.

Step 5: Check the Java version

java -version

The output confirms the active runtime:

openjdk version "11.0.21" 2023-10-17 LTS
OpenJDK Runtime Environment (build 11.0.21+9-LTS)
OpenJDK 64-Bit Server VM (build 11.0.21+9-LTS, mixed mode, sharing)

If you installed the devel package, check the compiler too:

javac -version

Setting JAVA_HOME

Many applications — Tomcat, Maven, Elasticsearch — expect JAVA_HOME to be set. Find the install path, then export it:

sudo update-alternatives --config java

Take the path shown, drop the trailing /bin/java, and add it to your profile so it survives a reboot:

echo 'export JAVA_HOME=/usr/lib/jvm/java-11-openjdk' | sudo tee -a /etc/profile.d/java.sh
source /etc/profile.d/java.sh
echo $JAVA_HOME

Running more than one Java version

You can install several JDKs side by side and switch the system default with the alternatives system:

sudo alternatives --config java

Pick the number for the version you want. Run the same command with --config javac to switch the compiler independently of the runtime.

That is the whole install: update, install the runtime, add the JDK if you compile, verify, and point JAVA_HOME at it.

How to install java on CentOs.