Tomcat does not recognize JAVA_HOME

There is a help text in catalina.sh. I will quote it here:

#   Do not set the variables in this script. Instead put them into a script
#   setenv.sh in CATALINA_BASE/bin to keep your customizations separate.

#
#   JAVA_HOME       Must point at your Java Development Kit installation.
#                   Required to run the with the "debug" argument.

# Ensure that any user defined CLASSPATH variables are not used on startup,
# but allow them to be specified in setenv.sh, in rare case when it is needed.
CLASSPATH=

if [ -r "$CATALINA_BASE/bin/setenv.sh" ]; then
  . "$CATALINA_BASE/bin/setenv.sh"
elif [ -r "$CATALINA_HOME/bin/setenv.sh" ]; then
  . "$CATALINA_HOME/bin/setenv.sh"
fi

When you starting tomcat using catalina.sh, it searching for file setenv.sh and sourcing it. It is searching in CATALINA_HOME or CATALINA_BASE.

So the better way to set JAVA_HOME for the tomcat is:

1. Create a script named setenv.sh in the folder CATALINA_BASE/bin, if it does not exist already.

2. Add this line to setenv.sh

   export JAVA_HOME=/opt/java/jdk1.8.0_05
   

3. Make it executable.

---

Why you should use this solution:

Setting environment variable in script is safer. Always try to set variables as locally as possible. Try do not use /etc/environment, /etc/profile and others if you really do not need Global Environment Variable. Setting JAVA_HOME in setenv.sh gives you ability to use different tomcats with different applications that need different version of java, but running by one user. Other user environment would not be affected by you.

Since you have set the environment variable for your own user and not for the superuser, you have two options:

1. You will have to export the variable using -E option as follows:

   sudo -E /opt/tomcat7/apache-tomcat-7.0.53/bin/startup.sh
   

   Note that this will export all environment variables while running the command. This is not preferred since the normal users environment is spilled out when you run the command as root. This is not desirable.

2. Export the variable in root's .bashrc /etc/enviroment file. Open a terminal and type:

   sudo nano /etc/environment
   

   and enter your administrative password, and add the following lines to the end of the file:

   JAVA_HOME=/opt/java/jdk1.8.0_05
   PATH=$PATH:$JAVA_HOME/bin
   

   and then

   source /etc/environment
   

   or restart your machine and then retry the command you were using.

---

Update:

This answer provided hints as two why step 2 wouldn't work, sudo would reset the environment and provide a secure path, so all global variables are reset. A workaround would be to use

sudo su

and then execute command which uses the set environment variables.