If you want to have the original Oracle JDK instead of OpenJDK, follow this:

1. Download the *.tar.gz file (e.g. jdk-10.0.2_linux-x64_bin.tar.gz) at https://www.oracle.com/technetwork/java/javase/downloads/jdk10-downloads-4416644.html
2. untar it to /opt

tar xvzf jdk-8u191-linux-x64.tar.gz --directory=/opt

3. Update the alternatives so the system knows about your Java version (the pathes have to be changed)

update-alternatives --install \
    /usr/bin/java java /opt/jdk1.8.0_191/bin/java 20000 \
    --slave /usr/bin/keytool keytool /opt/jdk1.8.0_191/bin/keytool \
    --slave /usr/bin/orbd orbd /opt/jdk1.8.0_191/bin/orbd \
    --slave /usr/bin/pack200 pack200 /opt/jdk1.8.0_191/bin/pack200 \
    --slave /usr/bin/policytool policytool /opt/jdk1.8.0_191/bin/policytool \
    --slave /usr/bin/rmid rmid /opt/jdk1.8.0_191/bin/rmid \
    --slave /usr/bin/rmiregistry rmiregistry /opt/jdk1.8.0_191/bin/rmiregistry \
    --slave /usr/bin/tnameserv tnameserv /opt/jdk1.8.0_191/bin/tnameserv \
    --slave /usr/bin/unpack200 unpack200 /opt/jdk1.8.0_191/bin/unpack200

4. change the defualt java:

update-alternatives --config java

5. check the version

 java -version

remove old java

update-alternatives --remove "java" "/opt/jdk1.8.0_151/bin/java"
rm -r /opt/jdk1.8.0_151/bin/java