查看安装的JDK
rpm -qa |grep java
卸载
rpm -e --nodeps java-1.8.0-openjdk-headless-1.8.0.242.b08-1.el7.x86_64 rpm -e --nodeps java-1.8.0-openjdk-1.8.0.242.b08-1.el7.x86_64 rpm -e --nodeps java-1.7.0-openjdk-headless-1.7.0.251-2.6.21.1.el7.x86_64 rpm -e --nodeps java-1.7.0-openjdk-1.7.0.251-2.6.21.1.el7.x86_64
卸载完成