Set JAVA_HOME in Ubuntu

Ref from 'askubuntu.com'


Three files you could edit, '/etc/environment' is the one prefered in web post:
/etc/environment
/etc/profile
~/.bashrc

But I chose adding file: /etc/profile.d/dnm-build-envsetting.sh

- Reboot pc, and all environments variables settings remains.
        qyang@lgm-pc:~$ cat /etc/environment
        PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games"
        qyang@lgm-pc:~$ cat /etc/profile.d/dnm-build-envsetting.sh
        # Some environmental variables required for DmM builder to work for android build.
        # 2017-JUN-09
        JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64
        ANDROID_HOME=/home/qyang/sandbox/android-sdk-linux
        QTDIR=/home/qyang/sandbox/qt-everywhere-opensource-4.8.7
        export JAVA_HOME
        export ANDROID_HOME
        export QTDIR

My old settings:
yang@lgm-pc:~/testsetupscript$ cat /etc/environment
PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games"
qyang@lgm-pc:~/testsetupscript$ cat /etc/profile
# /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

# The default umask is now handled by pam_umask.
# See pam_umask(8) and /etc/login.defs.

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_HOME=/usr/local/java/jdk1.8.0_25
PATH=$PATH:$HOME/bin:$JAVA_HOME/bin
export JAVA_HOME
export PATH