rpm -qa|grep java

表示没有安装jre
如果已经安装请先卸载
yum list java*

yum -y install java-1.8.0-openjdk*
java -version

ok
which is java

ls -lrt /usr/bin/java

ls -ltr /etc/alternatives/java

找到JDK /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.111-2.b15.el7_3.x86_64
cat >>/etc/profile<<!
export JAVA_HOME=/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.111-2.b15.el7_3.x86_64
export PATH=$JAVA_HOME/bin:$PATH
export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar
!
source /etc/profile

ok jdk安装完成
原文:http://www.cnblogs.com/yun965861480/p/6246460.html