yes the active jdk is ubuntu's


› dpkg-query -W 'openjdk-11*'                                                                                                                                                          
openjdk-11-demo	
openjdk-11-jdk:amd64	11.0.7+10-3ubuntu1
openjdk-11-jdk-headless:amd64	11.0.7+10-3ubuntu1
openjdk-11-jre:amd64	11.0.7+10-3ubuntu1
openjdk-11-jre-headless:amd64	11.0.7+10-3ubuntu1
openjdk-11-source	11.0.7+10-3ubuntu1

› update-alternatives --get-selections | grep jdk                                                                                                                                      
jaotc                          auto     /usr/lib/jvm/java-11-openjdk-amd64/bin/jaotc
jar                            auto     /usr/lib/jvm/java-11-openjdk-amd64/bin/jar
jarsigner                      auto     /usr/lib/jvm/java-11-openjdk-amd64/bin/jarsigner
java                           auto     /usr/lib/jvm/java-11-openjdk-amd64/bin/java
javac                          auto     /usr/lib/jvm/java-11-openjdk-amd64/bin/javac
javadoc                        auto     /usr/lib/jvm/java-11-openjdk-amd64/bin/javadoc
javap                          auto     /usr/lib/jvm/java-11-openjdk-amd64/bin/javap
jcmd                           auto     /usr/lib/jvm/java-11-openjdk-amd64/bin/jcmd
jconsole                       auto     /usr/lib/jvm/java-11-openjdk-amd64/bin/jconsole
jdb                            auto     /usr/lib/jvm/java-11-openjdk-amd64/bin/jdb
jdeprscan                      auto     /usr/lib/jvm/java-11-openjdk-amd64/bin/jdeprscan
jdeps                          auto     /usr/lib/jvm/java-11-openjdk-amd64/bin/jdeps
jexec                          auto     /usr/lib/jvm/java-11-openjdk-amd64/lib/jexec
jfr                            auto     /usr/lib/jvm/java-11-openjdk-amd64/bin/jfr
jhsdb                          auto     /usr/lib/jvm/java-11-openjdk-amd64/bin/jhsdb
jimage                         auto     /usr/lib/jvm/java-11-openjdk-amd64/bin/jimage
jinfo                          auto     /usr/lib/jvm/java-11-openjdk-amd64/bin/jinfo
jjs                            auto     /usr/lib/jvm/java-11-openjdk-amd64/bin/jjs
jlink                          auto     /usr/lib/jvm/java-11-openjdk-amd64/bin/jlink
jmap                           auto     /usr/lib/jvm/java-11-openjdk-amd64/bin/jmap
jmod                           auto     /usr/lib/jvm/java-11-openjdk-amd64/bin/jmod
jps                            auto     /usr/lib/jvm/java-11-openjdk-amd64/bin/jps
jrunscript                     auto     /usr/lib/jvm/java-11-openjdk-amd64/bin/jrunscript
jshell                         auto     /usr/lib/jvm/java-11-openjdk-amd64/bin/jshell
jstack                         auto     /usr/lib/jvm/java-11-openjdk-amd64/bin/jstack
jstat                          auto     /usr/lib/jvm/java-11-openjdk-amd64/bin/jstat
jstatd                         auto     /usr/lib/jvm/java-11-openjdk-amd64/bin/jstatd
keytool                        auto     /usr/lib/jvm/java-11-openjdk-amd64/bin/keytool
pack200                        auto     /usr/lib/jvm/java-11-openjdk-amd64/bin/pack200
rmic                           auto     /usr/lib/jvm/java-11-openjdk-amd64/bin/rmic
rmid                           auto     /usr/lib/jvm/java-11-openjdk-amd64/bin/rmid
rmiregistry                    auto     /usr/lib/jvm/java-11-openjdk-amd64/bin/rmiregistry
serialver                      auto     /usr/lib/jvm/java-11-openjdk-amd64/bin/serialver
unpack200                      auto     /usr/lib/jvm/java-11-openjdk-amd64/bin/unpack200