Today we will be going through the installation of Oracle Java SE which includes Java Development Kit (JDK) and Java Runtime Environment (JRE) on Debian 10 / Debian 9.
Java JDK is the most important one for the developers, and this guide will be more useful for them to build a development environment when they especially use the Debian operating system.
Prerequisites
To be able to install Oracle Java JDK, you need to log in as a user with sudo privileges.
Download Oracle Java
You can either use command line or browser to download the Java SE. Better use the browser as the command-line link may change when the new version is released.
Visit the Oracle Java SE page to download.
Oracle JDK 12:
Download Oracle JDK 12 (v12.0.2)
Oracle JDK 11 (LTS):
Download Oracle JDK 11 (v11.0.4) (Login Required)
Oracle JDK 8:
Download Oracle JDK 8 (v8u221) (Login Required)
If you still want to use the command line, use the below command.
### Oracle JDK 12 ### wget --no-check-certificate --no-cookies --header "Cookie: oraclelicense=accept-securebackup-cookie" https://download.oracle.com/otn-pub/java/jdk/12.0.2+10/e482c34c86bd4bf8b56c0b35558996b9/jdk-12.0.2_linux-x64_bin.deb ### Oracle JDK 11 ### LOGIN REQUIRED. USE WEB BROWSER TO DOWNLOAD. ### Oracle JDK 8 ### LOGIN REQUIRED. USE WEB BROWSER TO DOWNLOAD.
Install Oracle Java
Depending on the type of package and the version you have download, execute the command to install or extract Oracle Java.
### Oracle JDK 12 ### sudo apt install ./jdk-12.0.2_linux-x64_bin.deb ### Oracle JDK 11 ### sudo apt install ./jdk-11.0.4_linux-x64_bin.deb ### Oracle JDK 8 ### sudo tar -zxvf jdk-8u221-linux-x64.tar.gz -C /usr/lib/jvm/
Now, run update-alternatives command to install the Java on the system.
### Oracle JDK 12 ### sudo update-alternatives --install /usr/bin/java java /usr/lib/jvm/jdk-12.0.2/bin/java 1 ### Oracle JDK 11 ### sudo update-alternatives --install /usr/bin/java java /usr/lib/jvm/jdk-11.0.4/bin/java 2 ### Oracle JDK 8 ### sudo update-alternatives --install /usr/bin/java java /usr/lib/jvm/jdk1.8.0_221/bin/java 3
Set Default Java Version
Set the default java using the below command.
sudo update-alternatives --config java
If the system has multiple versions of JAVA, then the above command may list it all, like below.
Change the default Java version by typing number under Selection column and then press enter.
Here, I chose to have Oracle JDK 11 as the default Java version on the system.
Verify Java Version
Once you have set up the alternatives, then check the java version using the following command.
java -version
Output:
java version "11.0.4" 2019-07-16 LTS Java(TM) SE Runtime Environment 18.9 (build 11.0.4+10-LTS) Java HotSpot(TM) 64-Bit Server VM 18.9 (build 11.0.4+10-LTS, mixed mode)
The output will vary depending upon the version of Oracle Java installation.
Setup Environmental Variable
Some Java application installations require prior configuration of environmental variables like JAVA_HOME, JRE_HOME, etc. So, you can set the environmental variables like below.
Oracle Java 12:
export PATH=$PATH:/usr/lib/jvm/jdk-12.0.2/bin export JAVA_HOME=/usr/lib/jvm/jdk-12.0.2/ export J2SDKDIR=/usr/lib/jvm/jdk-12.0.2/
Oracle Java 11:
export PATH=$PATH:/usr/lib/jvm/jdk-11.0.4/bin export JAVA_HOME=/usr/lib/jvm/jdk-11.0.4/ export J2SDKDIR=/usr/lib/jvm/jdk-11.0.4/
Oracle Java 8:
export PATH=$PATH:/usr/lib/jvm/jdk1.8.0_221/bin export JAVA_HOME=/usr/lib/jvm/jdk1.8.0_221/ export JRE_HOME=/usr/lib/jvm/jdk1.8.0_221/jre/ export J2SDKDIR=/usr/lib/jvm/jdk1.8.0_221/ export J2REDIR=/usr/lib/jvm/jdk1.8.0_221/jre/
To set the environment variables permanent, place the above variables in the /etc/profile/java.sh (All Users) or ~/.bash_profile (Single User) file.
Conclusion
That’s All. Hope this post helped you install Oracle Java on your Debian 10 / Debian 9. Java is a must to run applications such as Tomcat, Gradle, ELK Stack, Graylog, Eclipse IDE, etc.
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