Vscode-java: JAVA_HOME is not pointing to a JDK.

[phhoef]

[provide a description of the issue]

Environment

• Operating System: macOS Mojave

• JDK version: OpenJDK 11.4

• Visual Studio Code version: 1.38.1
• Java extension version: 0.48.0

Steps To Reproduce

1. Opening Java Project

Current Result

After opening a Java project, the configure window pops up and shows, that the JAVA_HOME is set, but it's not pointing to a JDK.

The JAVA_HOME path is correctly set.

Expected Result

JDK should be found.

[Eskibear]

FYI, I've just tried the latest AdoptOpenJDK 11, and it works well for me.

A JDK(instead of JRE) is required. Please check

• if bin/javac exists under JAVA_HOME? e.g. using command ls $JAVA_HOME/bin/javac.

[phhoef]

I installed OpenJDK 11 via Homebrew.
javac exists in the bin directory.

➜  ~ ls $JAVA_HOME/bin/javac
/Library/Java/JavaVirtualMachines/adoptopenjdk-11.jdk/Contents/Home/bin/javac

➜  ~ /usr/libexec/java_home -V
Matching Java Virtual Machines (1):
    11.0.4, x86_64: "AdoptOpenJDK 11"   /Library/Java/JavaVirtualMachines/adoptopenjdk-11.jdk/Contents/Home

/Library/Java/JavaVirtualMachines/adoptopenjdk-11.jdk/Contents/Home

I can call java or javac from iTerm (zsh) without any problems.
Maven does also recognize the JDK. It seems that it's just VScode that does not work.

I also tried setting the java.home property in the user settings of VScode.
Then, the path is shown in the overview, but again it says the path is invalid.

[Eskibear]

I thought it was Homebrew issue, (e.g. privileges etc.), then I just reinstalled my OpenJDK11 via Homebrew, and it still works.

In your case, now all I can see is: you do have bin/javac under JAVA_HOME but the test pathExists.sync(path.resolve(javaHome, 'bin', JAVAC_FILENAME) fails, for both vscode-java and Java Home Configure Page

@fbricon @akaroml Any thoughts?

[phhoef]

hmm, that's weird.
Is it possible, to easily debug the mentioned lines?

Maybe it's still a problem with permissions?

➜  Home ls -la
total 8
drwxr-xr-x  12 root  wheel   384 23 Aug 19:18 .
drwxr-xr-x   5 root  wheel   160 23 Aug 15:39 ..
drwxr-xr-x  34 root  wheel  1088 23 Aug 15:45 bin
drwxr-xr-x   3 root  wheel    96 23 Aug 19:18 bundle
drwxr-xr-x   7 root  wheel   224 23 Aug 15:39 conf
drwxr-xr-x   5 root  wheel   160 23 Aug 15:39 demo
drwxr-xr-x   9 root  wheel   288 23 Aug 15:39 include
drwxr-xr-x  72 root  wheel  2304 23 Aug 15:39 jmods
drwxr-xr-x  72 root  wheel  2304 23 Aug 15:39 legal
drwxr-xr-x  57 root  wheel  1824 23 Aug 15:45 lib
drwxr-xr-x   5 root  wheel   160 16 Sep 11:14 man
-rwxr-xr-x   1 root  wheel  1221 23 Aug 15:39 release

I did't changed the permissions for these folders, but I had installed Oracle JDK before.
I removed it yesterday and switched to OpenJDK.

[Eskibear]

The permission looks good.
Is it possible that the VSCode process still has the out-dated JAVA_HOME which is pointing to your deleted OracleJDK? You can have a try to fully quit the VSCode via cmd + q, and restart VS Code from a terminal where JAVA_HOME has the correct value. (The java.home setting has the highest priority, if a valid java.home setting also fails as you mentioned above, then I've no idea what's happening.)

BTW, if java runtime cannot be recognized, an error box will popup on the bottom-right, which might carry more detailed info.

If you want to debug the extension, you need to have NodeJS installed. The java-pack extension is more easier for you to get started.

• clone it, run npm install
• open the folder in VS Code, set the breakpoint mentioned above, press F5.
• in the newly created Extension Host window, cmd+ shift + p, run "Configure Java Runtime" to trigger the breakpoint manually.

[phhoef]

I tried to open another Java project and it seems that with this project the JDK can be found - at least the messages are not popping up.

I closed VScode and opened the first project: Again the same error.

The error box pops up, but does not have really more information. Please see the attached screenshot.

Now, it's getting really weird.
I quit VSCode and opened it again through the terminal.

➜  ~ echo $JAVA_HOME
/Library/Java/JavaVirtualMachines/adoptopenjdk-11.jdk/Contents/Home
➜  ~ open /Applications/Visual\ Studio\ Code.app

And actually, the error is gone.
The path $JAVA_HOME path is exactly the same as shown in the error message.

Now, when opening VSCode directly without the Terminal, it still works.
I have no clue, what's going on ...

[Eskibear]

@phhoef I guess you did set the wrong JAVA_HOME, by appending an extra whitespace.

From the bottom-left error box in your screenshot, you can see there is a whitespace before ), and check the source code, it must be from your JAVA_HOME.

Back to compare the original screenshots, you can see more clear that your JAVA_HOME was longer than mine, with an extra whitespace.

[phhoef]

True, that could be the problem.
Actually, I didn't set the JAVA_HOME by myself, but Homebrew did it for me during cask install.

It still feels strange. I didn't change the JAVA_HOME, just opened VSCode through the terminal and then it started working.

Anyhow, I think it's found now, except when I open the pom.xml from the project.
The message box in the lower right corner pops up showing "The JAVA_HOME environment variable points to a missing folder".
As you see on the screenshot in the console, the Java server has been successfully started.
The message comes from the XML extension (redhat.vscode-xml).

I am not sure if this is related to the original problem.
I echoed the JAVA_HOME into a text file and at least for the Terminal there was no trailing whitespace.

P.S.
In the meantime I downgraded to OpenJDK 8, as some projects were not JDK 11 compatible.
The message box also pop ups with JDK 11 installed.

----- EDIT:
I opened the "Configure Java Runtime" manually, and actually it still says that the path is wrong.
The page won't open automatically on startup and also the message box doesn't appear at start (only when opening pom.xml)

This is also true, when opening VScode through terminal

[prasada7]

I had the same problem on my Mint. The problem was fixed after I reinstalled openjdk-11.
I used the following command. Should work for Ubuntu as well.
sudo apt install openjdk-11-*

[varrix]

Not sure why this coninues to be an issue for me. I enjoy using VSC for quick edits where VI* isn't the only option available. Although with my $JAVA_HOME set, exported automatically, and picked up on automatically by other IDEs such as IntelliJ, Eclipse, AND NetBeans... VSC even shows the path it found, but instead decides to mention that in my settings "$JAVA_HOME" is an invalid path..? wuh wuh?

Advice for a JDK8 user?

[gablex]

I have same issue on Fedora 32. I have set all paths as required but still issues

[fbricon]

@gablex dis you install vscode via flatpack? Many reports indicates flatpack vscode can't access Java home, because of the sandbox nature of flatpack

[gablex]

No, I used below commands after adding repo as stated in [https://code.visualstudio.com/docs/setup/linux]

sudo dnf check-update
sudo dnf install code

[gablex]

I have tried creating a direct path name on VC but says that my path doesn't point to JDK Installation

[gablex]

/usr/local/java/jdk-14.0.1+7 InvalidThis path is not pointing to a JDK. | JAVA_HOME | Environment Variable
-- | -- | --

[agilob]

On ArchLinux with sdkman:

this path is incorrect and says it's invalid directory for JDK
"java.home": "/home/agilob/.sdkman/candidates/java/14.0.1-open",

but this symlink works - and it points to the directory above:
"java.home": "/home/agilob/.sdkman/candidates/java/current",

[fbricon]

try "java.home": "/home/agilob/.sdkman/candidates/java/14.0.1.hs-adpt" there's no 14.0.1-open in your candidates directory.

[rajinder-yadav]

Getting same error on Linux openSUSE,

The JAVA_HOME environment variable (/usr/lib64/jvm/java-11-openjdk-11) does not point to a JDK.

JAVA_HOME set correctly:

export JAVA_HOME=/usr/lib64/jvm/java-11-openjdk-11

[UPDATE]:
It seems what I had install was only the JRE even though it's named openjdk?

I ended up downloading the package suggested to my by vscode in the, "Configure Java Runtime" setting, point JAVA_HOME to it and everything works, no errors.

You can also down the jdk from here: https://jdk.java.net/

Update A better solution might be to use SDKMAN to install java, jdk and sdk! https://sdkman.io/

[Eskibear]

Let me help to form a guide from most of above cases.

Root cause

Because of the confusing name of packages, some Linux users actually installed a JRE (Java Runtime Environment) instead of a JDK (Java Development Kit).
As ./bin/javac doesn't exists under path of Java home folder, the extension recognizes it as a JRE instead of a JDK (which is required), thus prints this error message.

Follow below steps to fix it

• Open command palette, run "Java: Configure Java Runtime", to find out which java homedir is taking effect.
  
  
  
  • If you don't have the command, install Java extension pack or follow the Setting the JDK to find out by your own.
  
  
• Check if .bin/javac exists under above path.
  
  
  
  • If yes, report to us with detailed information.
  
  
  • installed java packages on your Linux distribution
  
  
  • recognized java home directory
  
  
  • file permission of the related files
  
  
  • etc..
  
  
  • If no (most of the cases), try installing a JDK instead of JRE. E.g many packages have confusing names, make sure you installed the correct one
  
  
  • on Debian/Ubuntu, install openjdk-11-jdk with an additional jdk appended
  
  
  • others may append devel, src, all etc.
  
  

[gablex]

I am still stranded using java in visual code. I managed to solve missing JDK issue , however, when running my code I get below error:-
[Running] cd "/home/admin/Dev/Java/demo/src/main/java/com/martin/test/demo/" && javac DemoApplication.java && java DemoApplication /bin/sh: javac: command not found
My OS is Fedora 32.
Below is my javac test
$JAVA_HOME/bin/javac -version javac 14.0.1

[Eskibear]

@gablex I've never seen messages like "[running] cd ... ", and this extension doesn't call javac directly to compile your project. I guess you are talking about other extensions.

Just FYI, I use Language suport for Java for editing, and Debugger for Java to run/debug.

[gablex]

@Eskibear I agree. I have uninstalled all java plugins and installed java plugin pack only and now works

sh-5.0$ /home/admin/Downloads/Programs/jdk11/bin/java -Dfile.encoding=UTF-8 @/tmp/cp_8wzwvixrylq96snesdedrppha.argfile org.acme.martin.QuickStart Hello, World.
Thank all.

[RonaldinhoL]

i have the same problem on windows10 19042.423, i hava try adopt jdk 11 and oracle jdk 11, all the same problem.

[RobbiNespu]

As quick solution, just edit your vscode setting.json and pointing directly to java_home (eg: add "java.home": "C:\\java\\jdk\\java-11-openjdk-11.0.8-2", ). Please refer attached picture, saved it and vscode will ask to restart. After restart, should be no more same issue. I hope this will help.

[NoxFly]

Got the same error on Linux Debian 10.5 (buster).
I realized that if I was launching VSC by the application itself, it was doing this error, while if I launch VSC through the terminal, all's good. Maybe user's settings.

[lovexbma]

try cd your path in the terminal, if it fails, maybe the character format is wrong. then you could write the full path by keyboard, not Copy and Paste.