I had the same issue.
Info in repositories is not right.
If you follow logs you'll find the version you're installing is an archive. For me it was u191 today: 2019/01/16 but on website it's u201 or u202.
you have to change your repo info like this:
cd /var/lib/dpkg/info
sudo sed -i 's|JAVA_VERSION=8u191|JAVA_VERSION=8u201|' oracle-java8-installer.*
sudo sed -i 's|PARTNER_URL=http://download.oracle.com/otn-pub/java/jdk/8u191-b12/2787e4a523244c269598db4e85c51e0c/|PARTNER_URL=https://download.oracle.com/otn-pub/java/jdk/8u201-b09/42970487e3af4f5aa5bca3f542482c60/|' oracle-java8-installer.*
sudo sed -i 's|SHA256SUM_TGZ="53c29507e2405a7ffdbba627e6d64856089b094867479edc5ede4105c1da0d65"|SHA256SUM_TGZ="cb700cc0ac3ddc728a567c350881ce7e25118eaf7ca97ca9705d4580c506e370"|' oracle-java8-installer.*
sudo sed -i 's|J_DIR=jdk1.8.0_191J_DIR=jdk1.8.0_201|' oracle-java8-installer.*
Information is on Oracle's download website.
See answers to Can't install Oracle Java 8 in Ubuntu 16.04