How to uninstall the Java that comes with CentOS

Start with java-version to see your own Java version number

Then use RPM-E--nodeps [here, in turn, fill in the version number of the Java that comes with]

Download the JDK's GZ package online and configure it as follows

Here we need to find the profile file and add the environment variable:
#vim/etc/profile

Append the following information to the profile file:
Export java_home=/usr/java/jdk1.7.0
Export classpath=.: $JAVA _home/jre/lib/rt.jar: $JAVA _home/lib/dt.jar: $JAVA _home/lib/tools.jar
Export path= $PATH: $JAVA _home/bin

Save Exit, execute:
#source/etc/profile

How to uninstall the Java that comes with CentOS