Error: JAVA_HOME is not defined correctly executing maven

Question

I installed java and set path to environment and when I execute echo $JAVA_HOME I get the following output:

/usr/lib/jvm/java-7-oracle/jre/bin/j         


        

Answer 1

Assuming you use bash shell and installed Java with the Oracle installer, you could add the following to your .bash_profile

export JAVA_HOME=$(/usr/libexec/java_home)
export PATH=$JAVA_HOME/jre/bin:$PATH

This would pick the correct JAVA_HOME as defined by the Oracle installer and will set it first in your $PATH making sure it is found.

Also, you don't need to change it later when updating Java.

EDIT

As per the comments:

Making it persistent after a reboot

Just add those lines in the shell configuration file. (Assuming it's bash)

Ex: .bashrc, .bash_profile or .profile (for ubuntu)

Using a custom Java installation

Set JAVA_HOME to the root folder of the custom Java installation path without the $().

Ex: JAVA_HOME=/opt/java/openjdk

Answer 2

This solution work for me... just type export PATH=$JAVA_HOME/jre/bin:$PATH in the terminal then run mvn -version it will show the same error but with a log like this

which: no javac in (/jre/bin:/sbin:/bin:/usr/sbin:/usr/bin:/opt/puppetlabs/bin)
Warning: JAVA_HOME environment variable is not set.
Apache Maven 3.2.5 (12a6b3acb947671f09b81f49094c53f426d8cea1; 2014-12-14T22:59:23+05:30)
Maven home: /opt/apache-maven-3.2.5
Java version: 1.8.0_171, vendor: Oracle Corporation
Java home: /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.171-8.b10.el7_5.x86_64/jre
Default locale: en_US, platform encoding: UTF-8
OS name: "linux", version: "3.10.0-693.el7.x86_64", arch: "amd64", family: "unix"

now copy the Java home path i.e. /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.171-8.b10.el7_5.x86_64/jre in my case.

now type,

export JAVA_HOME=/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.171-8.b10.el7_5.x86_64/jre

and the error gets resolve. NOTE: paste your own path which is shown by your machine in mvn log at export JAVA_HOME.

Answer 3

You might get this error due to couple of reasons. To fix this quickly please follow below steps,

First find the java location. To get a list of your installed Java platforms, run the following command from the terminal:

$ sudo update-alternatives --config java

Now set JAVA_HOME and PATH,

$ export JAVA_HOME=<java_home>

$ export PATH=$JAVA_HOME/jre/bin:$PATH

Create the symlink

$ sudo ln -s <java_home>/jre <java_symlink_path>

When we take your case as a example :

$ sudo ln -s /usr/lib/jvm/java-7-oracle/jre /usr/lib/jvm/java-7-oracle/jre/bin/java

Above command will create the symlink location where the system is trying to find in your issue.

Finally do the

$ mvn --version

Answer 4

set as it is export JAVA_HOME=/usr/java/jdk1.8.0_31.and run with sudo it will execute..

Answer 5

Firstly, in a development mode, you should use JDK instead of the JRE. Secondly, the JAVA_HOME is where you install Java and where all the others frameworks will search for what they need (JRE,javac,...)

So if you set

JAVA_HOME=/usr/lib/jvm/java-7-oracle/jre/bin/java

when you run a "mvn" command, Maven will try to access to the java by adding /bin/java, thinking that the JAVA_HOME is in the root directory of Java installation.

But setting

JAVA_HOME=/usr/lib/jvm/java-7-oracle/

Maven will access add bin/java then it will work just fine.

Answer 6

You must take the whole directory where java is installed, in my case:

export JAVA_HOME=/usr/java/jdk1.8.0_31