问题
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
回答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
回答2:
JAVA_HOME should be /usr/lib/jvm/java-7-oracle/jre/
.
回答3:
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"
回答4:
$JAVA_HOME
should be the directory where java was installed, not one of its parts:
export JAVA_HOME=/usr/lib/jvm/java-7-oracle
回答5:
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
回答6:
You must take the whole directory where java is installed, in my case:
export JAVA_HOME=/usr/java/jdk1.8.0_31
回答7:
set as it is export JAVA_HOME=/usr/java/jdk1.8.0_31.and run with sudo it will execute..
回答8:
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.
回答9:
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.
回答10:
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 $JAVACMD"
exit 1
fi
Step3: It is happening because JAVACMD
variable was not set. So it displays the error.
Note: To Fix it
export JAVACMD=/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/jre/bin/java
export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/
Key: If you want it to be permanent open emacs .profile
post the commands and press Ctrl-x Ctrl-c ( save-buffers-kill-terminal ).
回答11:
If you are using mac-OS , export JAVA_HOME=/usr/libexec/java_home
need to be changed to export JAVA_HOME=$(/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
回答12:
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
回答13:
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
来源:https://stackoverflow.com/questions/27319495/error-java-home-is-not-defined-correctly-executing-maven