1.rpm下载地址
http://www.oracle.com/technetwork/java/javase/downloads/index.html
2.如果有安装openjdk 则卸载
########检查####################
[root@localhost ~]# rpm -qa | grep java
tzdata-java-2014i-1.el7.noarch
java-1.7.0-openjdk-headless-1.7.0.71-2.5.3.1.el7_0.x86_64
java-1.7.0-openjdk-1.7.0.71-2.5.3.1.el7_0.x86_64
##########卸载#################
rpm -e --nodeps tzdata-java-2014i-1.el7.noarch
rpm -e --nodeps java-1.7.0-openjdk-headless-1.7.0.71-2.5.3.1.el7_0.x86_64
rpm -e --nodeps java-1.7.0-openjdk-1.7.0.71-2.5.3.1.el7_0.x86_64
3.安装java rpm
rpm -ivh jdk-8u191-linux-x64.rpm
4.配置/etc/profile
#java
export JAVA_HOME=/usr/java/default
export PATH=$JAVA_HOME/bin:$PATH
export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar
5.source /etc/profile