安装openjdk失败，提示 E: Package 'openjdk-7-jdk' has no installation candidate

在Ubuntu 16.04LTS安装open jdk失败，提示 E: Package 'openjdk-7-jdk' has no installation candidate，原因是16.04源默认不含openjdk7，通过如下指令即可安装：

sudo add-apt-repository ppa:openjdk-r/ppa 
sudo apt-get update 
sudo apt-get install openjdk-7-jdk 

转自https://blog.csdn.net/brokge/article/details/51454265