jdk下载地址：
http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html

解压

1、mkdir /usr/local/java
2、cp jdk-8u181-linux-x64.tar.gz /usr/local/java

安装

解压：
tar xvf jdk-8u181-linux-x64.tar.gz

配置：

[root@bogon jdk1.8.0_181]# vim /etc/profile
# /etc/profile# System wide environment and startup programs, for login setup
# Functions and aliases go in /etc/bashrc# It's NOT a good idea to change this file unless you know what you
# are doing. It's much better to create a custom.sh shell script in
# /etc/profile.d/ to make custom changes to your environment, as this
# will prevent the need for merging in future updates.pathmunge () {case ":${PATH}:" in*:"$1":*);;*)if [ "$2" = "after" ] ; thenPATH=$PATH:$1elsePATH=$1:$PATHfiesac
}if [ -x /usr/bin/id ]; thenif [ -z "$EUID" ]; then# ksh workaroundEUID=`id -u`UID=`id -ru`fiUSER="`id -un`"LOGNAME=$USERMAIL="/var/spool/mail/$USER"
fi# Path manipulation
if [ "$EUID" = "0" ]; thenpathmunge /sbinpathmunge /usr/sbinpathmunge /usr/local/sbin
elsepathmunge /usr/local/sbin afterpathmunge /usr/sbin afterpathmunge /sbin after
fi"/etc/profile" 78L, 1796C                                                                                                                                1,1          顶端
for i in /etc/profile.d/*.sh ; doif [ -r "$i" ]; thenif [ "${-#*i}" != "$-" ]; then. "$i"else. "$i" >/dev/null 2>&1fifi
doneunset i
unset -f pathmungeexport JAVA_HOME=/usr/local/java/jdk1.8.0_181
export JRE_HOME=${JAVA_HOME}/jre
export CLASSPATH=.:${JAVA_HOME}/lib:${JRE_HOME}/lib
export PATH=${JAVA_HOME}/bin:$PATH

生效：

[root@bogon jdk1.8.0_181]# source /etc/profile
[root@bogon jdk1.8.0_181]#
[root@bogon jdk1.8.0_181]#
[root@bogon jdk1.8.0_181]# java -version
java version "1.8.0_181"
Java(TM) SE Runtime Environment (build 1.8.0_181-b13)
Java HotSpot(TM) 64-Bit Server VM (build 25.181-b13, mixed mode)