Class JavaLaunchHelper is implemented in both ... libinstrument.dylib. One of the two will be used. Which one is undefined

I upgraded to the latest Java 7u40 on MacOS X and started getting the following message on the console when launching my application using Eclipse. The app works fine but I would like to find out the cause of the problem and hopefully a fix for it.

objc[10012]: Class JavaLaunchHelper is implemented in both /Library/Java/JavaVirtualMachines/jdk1.7.0_40.jdk/Contents/Home/bin/java and /Library/Java/JavaVirtualMachines/jdk1.7.0_40.jdk/Contents/Home/jre/lib/libinstrument.dylib. One of the two will be used. Which one is undefined.

Does anyone know why this message is printed and how to fix it?

⚠️ For JetBrains IntelliJ IDEA: Go to Help -> Edit Custom Properties.... Create the file if it asks you to create it. To disable the error message paste the following to the file you created:

idea_rt
idea.no.launcher=true

This will take effect on the restart of the IntelliJ.

As of October 2017, this issue is now resolved in

• jdk1.9
• jdk1.8.152
• jdk1.7.161

1. Install Java 7u21 from: http://www.oracle.com/technetwork/java/javase/downloads/java-archive-downloads-javase7-521261.html#jdk-7u21-oth-JPR

2. Set these variables:

    export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.7.0_21.jdk/Contents/Home
    export PATH=$JAVA_HOME/bin:$PATH
   

3. Run your app and have fun :)

Copy Pasting @Lichtamberg's comments to gotoalberto's answer

Works also for Java 1.8:

# in ~/.zshrc and ~/.bashrc
 
export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0_92.jdk/Contents/Home 
export PATH=$JAVA_HOME/bin:$PATH 

This fixed my issue on java 8.

Not sure if this is the cause of the problem, but I got this issue only after installing JVM Monitor.

Uninstalling JVM Monitor solved the issue for me.

As other answers detail, this is a bug in the JDK (up to u45) which will be fixed in JDK7u60 - while this is not out yet, you may download the b01 from: https://jdk7.java.net/download.html

It's beta, but fixed that issue for me.

https://groups.google.com/forum/#!topic/google-appengine-stackoverflow/QZGJg2tlfA4

From what I've found online, this is a bug introduced in JDK 1.7.0_45. I've read it will be fixed in the next release of Java, but it's not out yet. Supposedly, it was fixed in 1.7.0_60b01, but I can't find where to download it and 1.7.0_60b02 re-introduces the bug.

I managed to get around the problem by reverting back to JDK 1.7.0_25. Probably not the solution you wanted, but it's the only way I've been able to get it working. Don't forget add JDK 1.7.0_25 in Eclipse after installing the JDK.

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To solve this issue, I downgraded to JDK version 1.7.0_21. then I used this little bash script to change the version I use.

function setjdk() {
  if [ $# -ne 0 ]; then
   removeFromPath '/System/Library/Frameworks/JavaVM.framework/Home/bin'
   if [ -n "${JAVA_HOME+x}" ]; then
    removeFromPath $JAVA_HOME
   fi
   export JAVA_HOME=`/usr/libexec/java_home -v $@`
   export PATH=$JAVA_HOME/bin:$PATH
  fi
 }

 function removeFromPath() {
  export PATH=$(echo $PATH | sed -E -e "s;:$1;;" -e "s;$1:?;;")
 }

Once you have the bash script in your zshrc/bshrc file, just call setJdk 1.7.0_21 and you're good to go.

Well, after some struggling, what worked for me was completely removing the current JDK, as described here:

sudo rm -rf /Library/Java/JavaVirtualMachines/jdk1.7.0_80.jdk
sudo rm -rf /Library/PreferencePanes/JavaControlPanel.prefPane
sudo rm -rf /Library/Internet\ Plug-Ins/JavaAppletPlugin.plugin
sudo rm -rf /Library/LaunchAgents/com.oracle.java.Java-Updater.plist
sudo rm -rf /Library/PrivilegedHelperTools/com.oracle.java.JavaUpdateHelper
sudo rm -rf /Library/LaunchDaemons/com.oracle.java.JavaUpdateHelper.plist
sudo rm -rf /Library/Preferences/com.oracle.java.Helper-Tool.plist

Then installed 1.7.0_21, which was downloaded from here.

Now java -version prompts:

java version "1.7.0_21"
Java(TM) SE Runtime Environment (build 1.7.0_21-b12)
Java HotSpot(TM) 64-Bit Server VM (build 23.21-b01, mixed mode)

July 2019

OSX Mojave 10.14.5 (18F132) IntelliJ 2019-1 Community Edition. It worked setting idea.properties file. I also configured JAVA_HOME pointing to /Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/

custom IntelliJ IDEA properties

idea_rt idea.no.launcher=true

If you're using IntelliJ & Mac just go to Project structure -> SDK and make sure that there is Java listed but it points to sth like

/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home

Rather than user home...

jdk-7u80-macosx-x64.dmg fix this problem.