CentOS install jdk1.8 environment

1.jdK is generally placed in the /usr/java directory

下载链接：http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html
[root@hadoop java]# mkdir -p /usr/java
[root@hadoop java]# cd /usr/java/
[root@hadoop java]# tar -xzvf jdk-8u171-linux-x64.gz
解压后可能用户用户组不对
可使用chown -R root:root jdk1.8.0_171 更改

2. Change environment variables

[root@hadoop java]# vi /etc/profile
export JAVA_HOME=/usr/java/jdk1.8.0_171
export PATH=$JAVA_HOME/bin:$PATH
之后source /etc/profile生效

3. Verify the environment

[root@hadoop java]# which java
/usr/java/jdk1.8.0_171/bin/java
[root@hadoop java]# java -version
java version "1.8.0_171"
Java(TM) SE Runtime Environment (build 1.8.0_171-b11)
Java HotSpot(TM) 64-Bit Server VM (build 25.171-b11, mixed mode)