Gradle finds wrong JAVA_HOME even though it's correctly set

Question

When trying to run gradle, I get the following error:

# gradle

ERROR: JAVA_HOME is set to an invalid directory: /usr/lib/jvm/default-java

Please set the JAVA_HOME variable in your environment to match the
location of your Java installation.

However, when I check the JAVA_HOME variable I get:

# echo $JAVA_HOME 
/usr/lib/jvm/java-7-oracle

My JAVA_HOME is defined in .bashrc and I have double checked that it is set as the source.

Running java -version also confirms that JAVA_HOME is set correctly and is on the PATH.

# java -version
java version "1.7.0_51"
Java(TM) SE Runtime Environment (build 1.7.0_51-b13)
Java HotSpot(TM) 64-Bit Server VM (build 24.51-b03, mixed mode)

I have also checked that /usr/bin/java symlinks to /etc/alternatives/java which in turn correctly symlinks to /usr/lib/jvm/java-7-oracle/jre/bin/java

Additionally I've checked that there are no duplicate JAVA_HOME definitions in .bash_profile or /etc/profile.

So my question is how/why does Gradle find /usr/lib/jvm/default-java, and more importantly how do I point it to the correct directory?

Other programs which require the JDK work fine, so I think its a Gradle issue. I've also tried reinstalling Gradle which made no difference.

I'm running 64bit Xubuntu (Ubuntu 13.10 base)

Solution 1

Turns out that the particular Gradle binary I downloaded from the Ubuntu 13.10 repository itself tries to export JAVA_HOME. Thanks to Lucas for suggesting this.

/usr/bin/gradle line 70:

export JAVA_HOME=/usr/lib/jvm/default-java

Commenting this line out solves the problem, and Gradle finds the correct path to the Java binary.

If you just download the binary from their website it does not have this problem, It's an issue with the Ubuntu repo version. There also seem to be some other issues with 13.10 version.

Solution 2

add a symbolic link

sudo ln -s /usr/lib/jvm/java-7-oracle /usr/lib/jvm/default-java

Solution 3

Solution is to make JAVA_HOME == dir above bin where javac lives as in

type javac

javac is /usr/bin/javac   # now check if its just a symlink

ls -la /usr/bin/javac 

/usr/bin/javac -> /etc/alternatives/javac   # its a symlink so check again

ls -la /etc/alternatives/javac  # now check if its just a symlink

/etc/alternatives/javac -> /usr/lib/jvm/java-8-openjdk-amd64/bin/javac

OK so finally found the bin above actual javac so do this

export JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64
export PATH=$JAVA_HOME/bin:$PATH

above can be simplified and generalized to

which javac >/dev/null 2>&1 || die "ERROR: no 'javac' command could be found in your PATH"
export JAVA_HOME=$(dirname $(dirname $(readlink -f $(which javac)  )))

Solution 4

For me this error was due to the reason Gradle as installed as sudo and I was trying as default user to run Gradle.

Try:

sudo gradle -version

or

sudo gradle -v

Solution 5

In my Ubuntu, I have a headache for 2 days on this issue.

Step 1. Type on the terminal whereis java then it will display something like this

java: /usr/bin/java /etc/java /usr/share/java /usr/lib/jvm/java-8-openjdk-amd64/bin/java /usr/share/man/man1/java.1.gz

Step 2. Take note of the path: /usr/lib/jvm/java-8-openjdk-amd64/bin/java

exclude the bin/java

your JAVA_HOME = /usr/lib/jvm/java-8-openjdk-amd64

View more solutions

Comments

[Peter Niederwieser]

Please provide the full error output. As it stands, it's not clear where the message comes from. Also, do you have a /usr/lib/jvm/default-java directory or symlink? And how did you install Gradle?

[James Barnett]

I've updated the Q, but that pretty much is the full error output. There is no /usr/lib/jvm/default-java dir. Installed with apt (apt-get install gradle)

[Peter Niederwieser]

The Gradle start script doesn't need JAVA_HOME to be set. If JAVA_HOME is set, the script uses $JAVA_HOME/bin/java to run Gradle. Otherwise, it uses java (i.e. java has to be on the PATH). Perhaps the (third-party) apt package uses a modified start script.

[James Barnett]

Yea looks like whatever ppa I got the binary from had hard coded and exported the JAVA_HOME to usr/lib/jvm/defult-java. Thanks for the help

[IgorGanapolsky]

Did you do source ~/.bashrc, or reboot your machine after setting JAVA_HOME?

[Manoj]

Just do export JAVA_HOME=/path/to/correct/java/version

[James Barnett]

Yes, its defined in .bashrc as export JAVA_HOME=/usr/lib/jvm/java-7-oracle (slightly different syntax but I assume its the same)

[Lucas]

@JamesBarnett, could the gradle command itself be setting that variable? Perhaps the person who installed gradle created a wrapper script that set environment variables before starting the application. When using tomcat, it is not uncommon for the catalina.sh (which is the startup script) to call out to a setenv.sh to set up environment variables which may include JAVA_HOME

[Ates Goral]

The gradle package appears to install the jdk to this location, at least on Ubuntu 12.04 LTS with only the default repositories. I did this on an Ubuntu VM that did not have Java, snapshotted it first, apt-get install gradle (which installs almost 400 packages), and it installed java to /usr/lib/jvm... reverted snapshot, no /usr/lib/jvm. I was testing the theory of gradle script exporting JAVA_HOME and indeed it does, as you found.

[Peter Niederwieser]

Gradle doesn't do this. The ppa is provided by someone else, and so you'd have to ask them. In general, I would recommend to bootstrap Gradle via the Gradle Wrapper, rather than installing it via a package manager.

[James Barnett]

I updated the answer to make it clearer that the Ubuntu repo version is the problem, not Gradle itself.

[Shashi]

@Nar could you please provide the installation path of JAVA

[Nar]

Thank you for answer but path of JAVA does not matter because gradle script overrides path as said James stackoverflow.com/a/22309017/1679348

[Kay Schneider]

Thank you, i search for over an hour for an solution to this problem. Thanks for this post, it solves my problem on ubuntu 14.04

[Phil]

Worked just fine for me. Given the name (default-java), I'd say this is a fairly sensible approach.

[sotrh]

Way to solve your own problem (and mine simultaneously)! It's a shame that this question is a year old and the Gradle script in the repository hasn't been updated to fix this.

[zorglub76]

In my opinion this is much better solution than changing Gradle files. (And yes, it works for me just fine)

[Jaymes Bearden]

Awesome. Problem is still around with Ubuntu 15.04

[Ian McLaird]

This answer would be improved if you explained what this command does and why it's needed.

[Basel Shishani]

We also now have sdkman (sdkman.io) to manage download/versions of gradle and other JVM sdk's.

[rahulrvp]

the newer version of android studio also has the same issue. but in a different way. it seems like they have resolved the export issue. but we have to call sudo ./gradlew install to get it work sometimes.

[Manoj]

I faced same issue. But in my GRADLE_HOME/bin/gradle file this line was not present - export JAVA_HOME=/usr/lib/jvm/default-java. Hence I couldn't figure out where does it pick the wrong one from. I am using gradle version 2.13 on RHEL 7.3. So to resolve this issue, I added the line export JAVA_HOME=/correct/path/to/java in GRADLE_HOME/bin/gradle file.

[Inessa Pokromkina]

also i put this to my ~/.bashrc to not enter this command everytime after reload export JAVA_HOME=/usr/lib/jvm/default-java

[Andy Lorenz]

its now 2019 and this is STILL an issue! Except its slightly different and the variable at fault is now "set JAVA_EXE=%JAVA_HOME%/bin/java.exe" - remove the bin part from here to fix.

[Borjante]

Key here is to exclude /bin/java

[Scott Stensland]

this is very fragile and will break once java gets upgraded to next release

[keocra]

I was able to solve the described issue by deleting the gradle wrapper from my project directory and re-initializing it with a newer system gradle (7.4.2). The issue was the 'goto init'. There are two lines which changed to 'goto execute'.