switch java version code example

Example 1: how to change java version in linux

$ sudo update-alternatives --config java

Example 2: change java version command line debian

sudo update-alternatives --config java

Example 3: change java version

/usr/libexec/java_home -V  
export JAVA_HOME=`/usr/libexec/java_home -v 1.6.0_65-b14-462` //java 8