I get the error below while trying to intall Oracle Java 8. Please tell me what's wrong.
$ sudo apt-get install oracle-java8-installer
[sudo] password for pragya:
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package oracle-java8-installer is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package 'oracle-java8-installer' has no installation candidate