Category: Ubuntu

✎ Last updated on 2018-05-15 at 12:30 EDT

[Updated for jdk-10.0.1]
This is for 64-bit installation.

1. Download JDK from Oracle site
   http://www.oracle.com/technetwork/java/javase/downloads
   The installation file I use is jdk-10.0.1_linux-x64_bin.tar.gz.
2. Change directory to install the JDK code in /opt

   cd /opt

3. extract the JDK files

   sudo tar -xvzf <location of downloaded JDK>/jdk-10.0.1_linux-x64_bin.tar.gz 

   This will put the JDK into the newly created directory named jdk-10.0.1

4. Update environment variables to point to the newly installed JDK by editing the /etc/environment file.

   sudo nano /etc/environment

   Add the JAVA_HOME variable, and add JDK bin to the PATH variable.

   JAVA_HOME="/opt/jdk-10.0.1"
   PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/opt/jdk-10.0.1/bin" 

5. Refresh the environment variable.

   source /etc/environment

6. Verify that the updated environment variables are in place and the path to the JDK is valid

   $ echo $JAVA_HOME
   /opt/jdk-10.0.1
   $ echo $PATH
   /usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/opt/jdk-10.0.1/bin
   

7. Update Java alternative list. You want to set a higher priority for the new JDK. On my system this is the result when I query the alternatives:

   $ update-alternatives --verbose --query java
   Name: java
   Link: /usr/bin/java
   Slaves:
    java.1.gz /usr/share/man/man1/java.1.gz
   Status: auto
   Best: /usr/lib/jvm/java-9-openjdk-amd64/bin/java
   Value: /usr/lib/jvm/java-9-openjdk-amd64/bin/java
   
   Alternative: /usr/lib/jvm/java-9-openjdk-amd64/bin/java
   Priority: 1091
   Slaves:
    java.1.gz /usr/lib/jvm/java-9-openjdk-amd64/man/man1/java.1.gz
   

   So, let’s make the new JDK our default…

   sudo update-alternatives --install /usr/bin/java java /opt/jdk-10.0.1/bin/java 10001

   The response is:

   update-alternatives: using /opt/jdk-10.0.1/bin/java to provide /usr/bin/java (java) in auto mode.

   Now, when you type java -version, you will see

   java version "1.0.1" 2018-04-17
   Java(TM) SE Runtime Environment 18.3 (build 1.0.0.1+10)
   Java HotSpot(TM) 64-Bit Server VM 18.3 (build 10.0.1+10, mixed mode)

8. Likewise, set the new Java compiler as default with

   $ sudo update-alternatives --install /usr/bin/javac javac /opt/jdk-10.0.1/bin/javac 10001
   update-alternatives: using /opt/jdk-10.0.1/bin/java to provide /usr/bin/javac (javac) in auto mode
   $ javac -version
   java version "10.0.1" 2018-04-17
   Java(TM) SE Runtime Environment 18.3 (build 10.0.1+10)
   Java HotSpot(TM) 64-Bit Server VM 18.3 (build 10.0.1+10, mixed mode)

9. If you wish, you can remove the link to the older java alternative

   $ sudo update-alternatives --verbose --remove java /usr/lib/jvm/java-9-openjdk-amd64/bin/java
   update-alternatives: discarding obsolete slave link java.1.gz (/usr/share/man/man1/java.1.gz)
   $ update-alternatives --verbose --query java
   Name: java
   Link: /usr/bin/java
   Status: auto
   Best: /opt/jdk-10.0.1/bin/java
   Value: /opt/jdk-10.0.1/bin/java
   
   Alternative: /opt/jdk-10.0.1/bin/java
   Priority: 10001
   

10. In the similar way, remove the old javac alternative link.

    $ update-alternatives --verbose --query javac
    Name: javac
    Link: /usr/bin/javac
    Slaves:
     javac.1.gz /usr/share/man/man1/javac.1.gz
    Status: auto
    Best: /opt/jdk-10.0.1/bin/java
    Value: /opt/jdk-10.0.1/bin/java
    
    Alternative: /opt/jdk-10.0.1/bin/java
    Priority: 10001
    Slaves:
    
    Alternative: /usr/lib/jvm/java-9-openjdk-amd64/bin/javac
    Priority: 1091
    Slaves:
     javac.1.gz /usr/lib/jvm/java-9-openjdk-amd64/man/man1/javac.1.gz
    $ sudo update-alternatives --remove javac /usr/lib/jvm/java-9-openjdk-amd64/bin/javac