Package 'openjdk-7-jdk' has no installation candidate

[ivanrome]

Hello,

Actually bthe build crash when trying to install openjdk-7

Package openjdk-7-jdk 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 'openjdk-7-jdk' has no installation candidate

docker-tutorial/Usecase-5/tomcat7-jdk7/Dockerfile

Line 45 in 875ddd6

RUN apt-get install -y openjdk-7-jdk