1.下载

http://download.oracle.com/otn-pub/java/jdk/8u112-b15/jdk-8u112-linux-x64.rpm

2.安装

rpm -ivh jdk-8u112-linux-x64.rpm

3.配置环境变量

gedit ~/.bashrc 
加入如下五行：
JAVA_HOME=/usr/java/jdk安装路径
JAVA_BIN=/usr/java/jdk安装路径/bin 
PATH=$PATH:$JAVA_HOME/bin 
CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar 
export JAVA_HOME JAVA_BIN PATH CLASSPATH 

4.创建链接

cd /usr/bin
ln -s -f /usr/local/jdk安装路径/jre/bin/java 
ln -s -f /usr/local/jdk安装路径/bin/javac