How to change Linux default Java compiler

1. Linux Java default is OpenJDK, I want to change Oracle Java SDK.
2. Download Oracle Java SDK
3. $ /usr/sbin/update-alternatives --install /usr/bin/java java "your download path"/bin/java 99
4. $ /usr/sbin/update-alternatives --config java
5. Choice your Oracle Java SDK.
6. Finish. 

P.S. Red words is command