[java] Error: JAVA_HOME is not defined correctly executing maven

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/java

I Also installed apache-maven and changed environment file and now it looks like this:

JAVA_HOME="/usr/lib/jvm/java-7-oracle/jre/bin/java"
M2_HOME=/usr/local/apache-maven/apache-maven-3.0.5
M2=$M2_HOME/bin
MAVEN_OPTS="-Xms256m -Xmx512m"
PATH=$M2:$PATH

But when I execute mvn --version I get a warning:

Error: JAVA_HOME is not defined correctly.
  We cannot execute /usr/lib/jvm/java-7-oracle/jre/bin/java/bin/java

Can not find out why it repeats in the end /bin/java/bin/java

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

It happens because of the reason mentioned below :

If you see the mvn script: The code fails here ---

Steps for debugging and fixing:

Step 1: Open the mvn script /Users/Username/apache-maven-3.0.5/bin/mvn (Open with the less command like: less /Users/Username/apache-maven-3.0.5/bin/mvn)

Step 2: Find out the below code in the script:

  if [ -z "$JAVACMD" ] ; then
  if [ -n "$JAVA_HOME"  ] ; then
    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
      # IBM's JDK on AIX uses strange locations for the executables
      JAVACMD="$JAVA_HOME/jre/sh/java"
    else
      JAVACMD="$JAVA_HOME/bin/java"
    fi
  else
    JAVACMD="`which java`"
  fi
fi

if [ ! -x "$JAVACMD" ] ; then
  echo "Error: JAVA_HOME is not defined correctly."
  echo "  We cannot execute $JAVACMD"
  exit 1
fi

Step3: It is happening because JAVACMD variable was not set. So it displays the error.

Note: To Fix it

export JAVACMD=/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/jre/bin/java

export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/

Key: If you want it to be permanent open emacs .profile

post the commands and press Ctrl-x Ctrl-c ( save-buffers-kill-terminal ).

JAVA_HOME should be /usr/lib/jvm/java-7-oracle/jre/.

I had this same issue but with open jdk and none of the answers here helped. The trouble was that the mvn script was appending /bin/java at the end of JAVA home while trying to run java commands.

The solution for me was to manually edit the /usr/local/apache-maven/apache-maven-3.3.9/bin/mvn script (your own script might be installed differently; just run which mvn) and change

   if [ -z "$JAVACMD" ] ; then
  if [ -n "$JAVA_HOME"  ] ; then
    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
      # IBM's JDK on AIX uses strange locations for the executables
      JAVACMD="$JAVA_HOME/jre/sh/java"
    else
      JAVACMD="$JAVA_HOME/bin/java" 
    fi
  else
    JAVACMD="`which java`"
  fi
 fi

To

if [ -n "$JAVA_HOME"  ] ; then
    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
      # IBM's JDK on AIX uses strange locations for the executables
      JAVACMD="$JAVA_HOME/jre/sh/java"
    else 
      JAVACMD="$JAVA_HOME"
    fi
  else
    JAVACMD="`which java`"
  fi
fi

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

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

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.

If you are using mac-OS , export JAVA_HOME=/usr/libexec/java_home need to be changed to export JAVA_HOME=$(/usr/libexec/java_home) . Steps to do this :

 $ vim .bash_profile

 export JAVA_HOME=$(/usr/libexec/java_home)

 $ source .bash_profile

where /usr/libexec/java_home is the path of your jvm

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

We open a terminal and look for the location of java:

manuel@zonademanel:~ ? whereis java

java: /usr/bin/java /etc/java /usr/bin/X11/java /usr/share/java /usr/share/man/man1/java.1.gz

What we are looking for is /usr/bin/java continue on the command line to find the absolute path , as this is only a symbolic link.

manuel@zonademanel:~ ? ls -lah /usr/bin/java

lrwxrwxrwx 1 root root 22 may 19 2015 /usr/bin/java -> /etc/alternatives/java

manuel@zonademanel:~ ? ls -lah /etc/alternatives/java

lrwxrwxrwx 1 root root 39 dic 7 11:52 /etc/alternatives/java -> /usr/lib/jvm/java-8-oracle/jre/bin/java

I modified my /etc/environment file with the following values

PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/usr/lib/jvm/java-8-oracle/jre/bin" JAVA_HOME="/usr/lib/jvm/java-8-oracle/jre"

If I do not want to relogin I can reload the changes with:

source /etc/environment 

??And run mvn -version correctly

manuel@zonademanel:~ ? mvn -version

Apache Maven 3.0.5
Maven home: /usr/share/maven
Java version: 1.8.0_77, vendor: Oracle Corporation
Java home: /usr/lib/jvm/java-8-oracle/jre
Default locale: es_MX, platform encoding: UTF-8
OS name: "linux", version: "3.16.0-70-generic", arch: "amd64", family: "unix"

In my case, the problem was in vscode.

I use windows and installed Ubuntu on my computer, so vscode terminal uses the Ubuntu. I just go to settings.json and change to cmd.exe again

$JAVA_HOME should be the directory where java was installed, not one of its parts:

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

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.

Use these two commands (for Java 8):

sudo update-java-alternatives --set java-8-oracle
java -XshowSettings 2>&1 | grep -e 'java.home' | awk '{print "JAVA_HOME="$3}' | sed "s/\/jre//g" >> /etc/environment