Ubuntu16.04 default Java set to Oracle in the jdk!

There is already a openjdk in the system, the default JDK is it, not the Oracle JDK, do the following to set the Oracle JDK as the default!

First, let's say we've installed and configured the Oracle JDK, but the "java-version" display in the shell is openjdk!

Execute the following command in turn:

sudo update-alternatives--install/usr/bin/java java/usr/jdk1.8.0_121/bin/java  sudo update-alternatives-- Install/usr/bin/javac Javac/usr/jdk1.8.0_121/bin/javac 300  

Note: The top two commands above, "/usr/jdk1.8.0_121" This is my Oracle JDK directory, if you are not this directory, you have to change to your correct directory!

After executing update-alternatives--config Java, the system lists all the JDK, we select the Oracle JDK index number, then the carriage return is possible!

Ubuntu16.04 default Java set to Oracle in the jdk!