Basically, you can try manually install Java 8 on ubuntu machine. In able to do that, follow these steps:
1. You need to download the latest Java 8 Development kit.
2. After that, type the command $mkdir /opt/jdk
3. After that, we need to untar java in new folder like : $tar -zxf jdk-8u5-linux-x64.tar.gz -C /opt/jdk