mkdir /usr/java
cp  jdk-8u181-linux-x64.tar.gz /usr/java
cd /usr/java/
chmod +x jdk-8u181-linux-x64.tar.gz 
tar -zxvf jdk-8u181-linux-x64.tar.gz 
vi /etc/profile 
export JAVA_HOME=/usr/java/jdk1.8.0_181
export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar
export PATH=$JAVA_HOME/bin:$PATH
source /etc/profile

这样的的话，root用户和普通用户都能访问到

针对ubuntu14 安装jdk1.8

chown esnew:esnew jdk-8u211-linux-x64.tar.gz 
tar -zxvf jdk-8u211-linux-x64.tar.gz 
vi ~/.bashrc
export JAVA_HOME=/home/esnew/jdk1.8.0_211
export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar
export PATH=$JAVA_HOME/bin:$PATH
source ~/.bashrc