How To Install Oracle Java 14 on Ubuntu 20.04

Search on google to download oracle jdk 14 ,go to oracle download page & select deb version,I am choosing 14 instead of 15 as Jhipster does not work with 15 version.While downloading you have to register to oracle site.

Now run

    sudo dpkg -i jdk-14_linux-x64_bin.deb
    
After this set the path to the Oracle Java executable    

    sudo update-alternatives --install /usr/bin/java java /usr/lib/jvm/jdk-14.0.2/bin/java 1
    sudo update-alternatives --install /usr/bin/javac javac /usr/lib/jvm/jdk-14.0.2/bin/javac 1

Choose from openjdk & oracle jdk
    sudo update-alternatives --config java

Output
    There are 2 choices for the alternative java (providing /usr/bin/java).

      Selection    Path                                         Priority   Status
    ------------------------------------------------------------
    * 0            /usr/lib/jvm/java-11-openjdk-amd64/bin/java   1111      auto mode
      1            /usr/lib/jvm/java-11-openjdk-amd64/bin/java   1111      manual mode
      2            /usr/lib/jvm/jdk-14.0.2/bin/java              1         manual mode

choose option number 2.

Now
    sudo update-alternatives --config javac
Output:
    There are 2 choices for the alternative javac (providing /usr/bin/javac).

      Selection    Path                                          Priority   Status
    ------------------------------------------------------------
      0            /usr/lib/jvm/java-11-openjdk-amd64/bin/javac   1111      auto mode
      1            /usr/lib/jvm/java-11-openjdk-amd64/bin/javac   1111      manual mode
    * 2            /usr/lib/jvm/jdk-14.0.2/bin/javac              1         manual mode
    
Choose option number 2.    
    

Now See which is your default JDK
 java --version
 
 output :
    java 14.0.2 2020-07-14
    Java(TM) SE Runtime Environment (build 14.0.2+12-46)
    Java HotSpot(TM) 64-Bit Server VM (build 14.0.2+12-46, mixed mode, sharing)
    
Setting JAVA_HOME enviornment variable

    Run
        sudo update-alternatives --config java
    output:
    There are 2 choices for the alternative java (providing /usr/bin/java).

          Selection    Path                                         Priority   Status
        ------------------------------------------------------------
          0            /usr/lib/jvm/java-11-openjdk-amd64/bin/java   1111      auto mode
          1            /usr/lib/jvm/java-11-openjdk-amd64/bin/java   1111      manual mode
        * 2            /usr/lib/jvm/jdk-14.0.2/bin/java              1         manual mode
    from here correct java path is "/usr/lib/jvm/jdk-14.0.2/bin/java"
        
    so the enviornment variable will be
        JAVA_HOME="/usr/lib/jvm/jdk-14.0.2"

    Open /etc/environment and add above line,

Now to reload enviornment variables run
    source /etc/environment