1、查看centos自带的jdk
rpm -qa | grep java
2、删除自带的jdk
例如:rpm -e --nodeps java-1.8.0-openjdk-1.8.0.102-4.b14.el7.x86_64
rpm -e --nodeps java-1.8.0-openjdk-headless-1.8.0.102-4.b14.el7.x86_64
rpm -e --nodeps java-1.7.0-openjdk-headless-1.7.0.111-2.6.7.8.el7.x86_64
rpm -e --nodeps java-1.7.0-openjdk-1.7.0.111-2.6.7.8.el7.x86_64
3、再去查看是否已经删除
rpm -qa | grep java
4、自己在配置相应的jdk