Install
详见水是全海大的Ubuntu 安装 JDK 7 / JDK8 的两种方式
smartxxyx的 ubuntu12下配置JDK，No such file or directory错误
！Note:
- 之前安装过Openjdk-7-jre的，导致8失败
hadoop@alphacoco:~$ sudo apt-get install openjdk-8-jre
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package openjdk-8-jre
解决方法：安装Oracle-8的版本
详见 stackoverflow上的Ubuntu: OpenJDK 8 - Unable to locate package
checksum for jdk-8u111-linux-x64.tar.gz
md5: 2d48badebe05c848cc3b4d6e0c53a457
