How to export the correct java version into a bash script

Ubuntu 18.04.6 LTS
Bash 4.4.0

I have 4 versions of java on my Linux box. I also have multiple MC Game Servers running on this box. When I run certain servers that require Java 8, I point to Java 8 like so:

#!/bin/bash

java="/usr/lib/jvm/java-8-openjdk-amd64/bin"  

When I run certain servers that require Java 16, I point to Java 16 like so:

#!/bin/bash

java="/usr/lib/jvm/java-16-oracle/bin"  

So in an attempt to properly import these versions of java into variables, I edited the /etc/profile file and everything from #== Java 7 and below is added by me:

# /etc/profile: system-wide .profile file for the Bourne shell (sh(1))
# and Bourne compatible shells (bash(1), ksh(1), ash(1), ...).

if [ "${PS1-}" ]; then
  if [ "${BASH-}" ] && [ "$BASH" != "/bin/sh" ]; then
    # The file bash.bashrc already sets the default PS1.
    # PS1='\h:\w\$ '
    if [ -f /etc/bash.bashrc ]; then
      . /etc/bash.bashrc
    fi
  else
    if [ "`id -u`" -eq 0 ]; then
      PS1='# '
    else
      PS1='$ '
    fi
  fi
fi

if [ -d /etc/profile.d ]; then
  for i in /etc/profile.d/*.sh; do
    if [ -r $i ]; then
      . $i
    fi
  done
  unset i
fi

#== Java 7
#== ======
JAVA7=/usr/lib/jvm/zulu7-ca-amd64
PATH=$PATH:$HOME/bin:$JAVA7/bin

#== Java 8
#== ======
JAVA8=/usr/lib/jvm/java-8-openjdk-amd64
PATH=$PATH:$HOME/bin:$JAVA8/bin

#== Java 11
JAVA11=/usr/lib/jvm/java-11-openjdk-amd64
PATH=$PATH:$HOME/bin:$JAVA11/bin

#== Java 16
JAVA16=/usr/lib/jvm/java-16-oracle
PATH=$PATH:$HOME/bin:$JAVA16/bin

export JAVA7
export PATH
export JAVA8
export PATH
export JAVA11
export PATH
export JAVA16
export PATH

If this is correct when I use JAVA16 in a script, how do I call for it in my start script?