如何测试是否为Tomcat正确设置了JAVA_HOME-variable

Question

I'm currently setting up a Tomcat Server under Ubuntu 14.10.

in ${CATALINA_HOME}/RUNNING.txt it says, that either JAVA_HOME or JRE_HOME need to be set. I filled the file ${CATALINA_HOME}/bin/setenv.sh with:

JAVA_HOME=/usr/lib/jvm/java-7-openjdk-amd64

since

sudo dpkg -L 'openjdk-7-jdk'

indicated that this is the place where my JDK is installed. To test the location, i also tried:

JAVA_HOME=/usr/lib/jvm/some-none-existing-place

which gave no error when starting tomcat using ${CATALINA_HOME}/bin/startup.sh (although the path does obviously not exist)

So, when is this variable used by Tomcat and how can I check if I set the correct path (for Tomcat)?

Answer 1

Type in terminal,

echo $JAVA_HOME

It will display JAVA_HOME variable path.

IF nothing appears then you can set it manually by,

export JAVA_HOME=/usr/lib/jvm/java-7-openjdk-amd64

This will differ according to your JDK type & version

Edit: Also you just follow the below to ensure you set in tomcat configuration file.

Hit Ctrl+Alt+T to open terminal and run:

sudo gedit /etc/default/tomcat7

Find commented JAVA_HOME , uncomment and change the directory to your JDK environment. Restart now and check for the error.

Answer 2

Open a command prompt, type :

java -version

java version "1.8.0_60" Java(TM)

SE Runtime Environment (build > 1.8.0_60-b27)

Java HotSpot(TM) 64-Bit Server VM (build 25.60-b23, mixed mode)

javac -version

javac 1.8.0_60

echo %JAVA_HOME%

C:\\Program Files\\Java\\jdk1.8.0_60

Answer 3

So, what is your problem:
a) Tomcat does not start, or
b) it starts, but you do not know what version of Java it is using?

1. Check that your setenv.sh file is readable. If it is not readable, it will be ignored.

2. If JRE_HOME variable is set then JAVA_HOME will be ignored.

   If neither one is set, then there are some defaults that are tried, including a call to which java . (The magic is in ${CATALINA_HOME}/bin/setclasspath.sh).

3. The ${CATALINA_HOME}/bin/version.sh script will print the versions of Tomcat and Java.

   Tomcat scripts print the actual value of JRE_HOME when Tomcat starts if you have a terminal. ( if [ $have_tty -eq 1 ]; block in catalina.sh).

   In recent versions of Tomcat a org.apache.catalina.startup.VersionLoggerListener can be configured in server.xml and will print the path to java and other settings. http://tomcat.apache.org/tomcat-8.0-doc/config/listeners.html