java7-sdk software package provides virtual package provided by default-jdk, openjdk-7-jdk, you can install in your Debian 8 (Jessie) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install java7-sdk
java7-sdk is installed in your system.
Make ensure the java7-sdk package were installed using the commands given below,
$ sudo dpkg-query -l | grep java7-sdk*
You will get with java7-sdk package name, version, architecture and description in a table
| Distro | Debian 8 jessie |
| Section | Virtual packages |
| Package | java7-sdk |
| Version | |
| Description | virtual package provided by default-jdk, openjdk-7-jdk |
| Sub Section | virtual |