Problems with JDK version conflicts in CentOS

In the CentOS environment, my JDK version installs the JDK6,JDK7. The system also comes with a JDK7. I'm looking at the JDK version, and I found that I didn't configure it in/etc/profile.

1:which Java

The command to view Java uses:/usr/bin/java

2:ll/usr/bin/java

lrwxrwxrwx 1 root root 22 March 11:38/usr/bin/java-/etc/alternatives/java

3:ll/etc/alternatives/java

The true path of the output command. Find the JDK path to a system

This needs to be modified using the alternatives command.

Alternatives--install "/usr/bin/javac" "Javac" "/usr/java/latest/bin/javac" 1

The last parameter represents a priority

Alternatives--config Java

Choose which path the Java command points to

Problems with JDK version conflicts in CentOS