You can check the java version by following the command. In Ubuntu, you can simply install Open JDK by following commands. It will display something like below, openjdk version '11.0.4'

*2 /usr/lib/jvm/java-8-openjdk-amd64/bin/javac 1081 manual modeģ /usr/lib/jvm/jdk1.8.0_211/bin/javac 0 manual mode Will result something like below, There are 3 choices for the alternative javac (providing /usr/bin/javac).Ġ /usr/lib/jvm/java-11-openjdk-amd64/bin/javac 1111 auto modeġ /usr/lib/jvm/java-11-openjdk-amd64/bin/javac 1111 manual mode You can select desired selection number, my case it's 0įor javac, sudo update-alternatives -config javac Press to keep the current choice, or type selection number: You can see java 1.11 available from above list, use below command to set java 11 to default, sudo update-alternatives -config javaįor above command, you will get something like below and also, will ask for an option to set, There are 3 choices for the alternative java (providing /usr/bin/java).Ġ /usr/lib/jvm/java-11-openjdk-amd64/bin/java 1111 auto modeġ /usr/lib/jvm/java-11-openjdk-amd64/bin/java 1111 manual mode You should see something like below, java-1.11.0-openjdk-amd64 1111 /usr/lib/jvm/java-1.11.0-openjdk-amd64 To make sure java version is 1.11.x, if found old one or different, check below command to see the available jdks, update-java-alternatives -list

Openjdk 11 source