CentOS7 install JDK

step1 uninstall openjdk

• yum -y remove java java-1.4.2-gcj-compat-1.4.2.0-40jpp.115

• yum -y remove java java-1.6.0-openjdk-1.6.0.0-1.7.b09.el5

step2 config environment variables

• vim /etc/profile, append the following

　　　　export JAVA_HOME=/usr/java/jdk1.8
　　　　export CLASSPATH=.:$JAVA_HOME/jre/lib/rt.jar:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar
　　　　export PATH=$PATH:$JAVA_HOME/bin

step3 make effect by cnd 'source /etc/profile'

step4 check by cmd 'java -version'