Download Java SDK and Install
1. Download Java SDK from Oracle websit
2.unzip by command line
tar -zvxf jdk-8u91-linux-x64.tar.gz /usr/lib/jvm
3.add JAVA_HOME to ~/.bashrc
export JAVA_HOME=/usr/lib/jvm/jdk1.8.0_91
4.
sudo update-alternatives --install /usr/bin/java java /usr/lib/jvm/jdk1.8.0_91/jre/bin/java 2
sudo update-alternatives --config java
OpenJDK: find openjdk by apt-cache search openjdk, then apt-get install
