Maven error: Could not find or load main class org.codehaus.plexus.classworlds.launcher.Launcher

java windows maven

I have installed a latest maven-3.0.4 on Windows 7:
The installation details are as follows:
Installation Path :

C:\apache-maven-3.0.4

Environment Variables are:

M2_HOME C:\apache-maven-3.0.4\apache-maven\src  
JAVA_HOME C:\Program Files\Java\jdk-1.7.0_04

Path variables added are:

%M2_HOME%\bin;%JAVA_HOME%\bin;

In the command window it shows it like this:

C:\>java -version  
java version "1.7.0_04"  
Java(TM) SE Runtime Environment (build 1.7.0_04-b22)  
Java HotSpot(TM) Client VM (build 23.0-b21, mixed mode, sharing)  
C:\>mvn -version  
Error: Could not find or load main class org.codehaus.plexus.classworlds.launcher.Launcher

This is the only version on maven installed on my PC and the solution given on many blogs referring to the deletion of the previous M2_HOME environment variable is not valid.

I have read and tried all the solutions given at blogs such as :

oracle blog,

stackoverflow question,

another stack question,

some blog,

but still not able to get to it. What I might be missing in this whole thing? Thanks in advance.

Just downloaded binary zip and it was broken. Replaced with .tar.gz and it works. So when M2_HOME is set correctly really try to check that what you downloaded is correct.

@PavelHoral same happened to me

I get this error on this jenkins only, via command like mvn compile working fine !

CodeRain

I hit this problem too, and found this article. For Maven3, changing my environment variable name from M2_HOME to M3_HOME did the trick. I am on a Mac running OSX 10.9 with JDK 1.7. Hope this helps.

Note: Please delete M2_HOME, if already set. Eg: unset M2_HOME

Same for me on a mac. Make sure you delete M2_HOME

Worked with Maven 3.3.3 binary, on Ubuntu. JAVA_HOME is not set.

This works as of Mac OS 10.10.5 with brew installed maven (3.3.3).

@Luke Thank you! unset M2_HOME.

This solution works, but not for the reasons you might think. The problem, as indicated in some of the comments of the referenced article, is not that M3_HOME is needed instead, but rather that M2_HOME is incorrectly defined. It seems that M3_HOME isn't used at all, so basically what's happening is the default is used when you delete M2_HOME.

Andrew Barber

Even though the question is answered I would like to add that, if you are getting the above mentioned error, be sure that you have downloaded the Binary file.

The source file should only be downloaded if you are an advanced user and that you know how to deal with it.

I have had quite a share of people downloading the wrong file, seniors and juniors

I actually downloaded the source on purpose, as that's the traditional way to do things, but I accidentally followed instructions for the binary installation. Just copying down the binary tar was actually easier in the long run.

+1: Same thing happened here - accidentally clicked on the wrong download link. Works not that I got the right zip file!

This single-handedly fixed the issue for me - thank you!

True. Downloaded source files and tried updating M3_HOME but didn't work. Binaries work good.

Just had this happen to me. The website is unclear on which to use.

Alex Fairchild

I was having this same problem and was able to resolve it by carefully redoing the Environment Variables:

M2_HOME

JAVA_HOME

Also, I made them all System Variables, not User Variables like the Maven instructions say. When you

echo %Path%

Make sure you can see the %M2% and %JAVA_HOME% variables completely expanded, i.e. :

C:\Users\afairchild>echo %Path%
C:\Program Files\Apache Software Foundation\apache-maven-3.0.4\bin;C:\Program Files\Java\jdk1.7.0_09\bin; [etc]

M2_HOME is the first thing to check if you are upgrading. JAVA_HOME should remain unchanged.

How is the M2 environment variable used? I only have JAVA_HOME and M2_HOME.

@KevinMeredith: The M2 environment variable is sometimes used to indicate the %M2_HOME\bin% path, which in turn is then added to the %Path% environment variable. This is needed when the Maven batch file mvn.bat cannot be found in the standard %Path% entries defined. A typical use case would be a non-standard installation directory for Maven.

@Alex I get this error on this jenkins only, via command like mvn compile working fine !

Joseph Lust

Had this issue on two different Ubuntu 12.04 installs, despite the installs being done by apt-get. Issue was M2_HOME.

Fixed with:

export M2_HOME=/usr/share/maven

It worked for me but with M2_HOME=/usr/share/maven2 (in case anyone else tries it). Thanks!

On Ubuntu, better create /etc/profile.d/maven.sh with the command you pointed: export M2_HOME=/usr/share/maven. As @jimkont pointed, sometimes is maven2, or maven3 (if you installed maven3, of course).

It works. Thanks. But can we just add it to the /etc/environtment file?

saravp

I believe this error caused because of downloading SRC instead of BINARY from Maven site. Please make sure to download Binary zip.

Because the below path, you will get only when you download SRC:

M2_HOME C:\apache-maven-3.0.4\apache-maven\src

https://i.stack.imgur.com/AJaKj.jpg

This worked for me. Follow the guide here: maven.apache.org/install.html and set your system PATH variable with C:\apache-maven-3.6.3\bin

very good hint , since there is also a bin folder inside a nested apache-maven folder of the SRC zip files!

jdmidtun

It sounds like you installed (extracted) the source files instead of the binaries based on your path information. Try installing the binaries instead and following the other posters answer.

Thanks fixed mine also. However, why can you not use the src download also, as long as it contains the correct execuatable in the bin dir?

Adelin

Well, I had this problem and after seeing this post and particularly khmarbaise answer I noticed that M2_HOME was

D:\workspace\apache-maven-3.1.0-bin\apache-maven-3.1.0\bin

and then I chaged it to

D:\workspace\apache-maven-3.1.0-bin\apache-maven-3.1.0

I would like to mention that I use windows 7 (x64)

I get this error on this jenkins only, via command like mvn compile working fine !

JESii

The solution for later versions of Maven is straight-forward. I am on OS X ElCap, 10.11.6 and upgraded to Maven 3.3.9. I had the same problem with error "Could not find ...org.codehaus.plexus...". The link provided here offered the solution in a comment by McKamey - simply delete M2_HOME (unset M2_HOME). Once I tried that, it all worked as expected.

This can be confirmed by visiting the Maven install page: "Add the bin directory of the created directory apache-maven-3.3.9 to the PATH environment variable" -- no mention of M2_HOME or M3_HOME at all.

Sreekanth

For most of the Maven setup issues something like "Could not find or load main class...", start-with below steps to see if that fixes:

Make sure you unzipped the right archive (BINARY archive and not SOURCE archive)

Remove all user and system variables related to Maven (ex. M2_HOME,M2_OPTS etc.)

Make sure JAVA_HOME system variable is setup (ex. "C:\Program Files\Java\jdk1.8.0_172")

Make sure java bin location is added in "path" system variable (ex. "%JAVA_HOME%\bin")

Make sure maven bin location is added in "path" system variable (ex. "C:\MyInstalls\apache-maven-3.5.4\bin")

then...

Verify java is setup (at commandprompt : java -version)

Verify maven is setup (at commandprompt : mvn --version)

Gastón Saillén

Open a new terminal and do the followin

M2_HOME=/Users/macbook/apache-maven-3.6.1 //Set where maven is
M2=$M2_HOME/bin                          //Set home as bin
export PATH=$M2:$PATH                   //Place the new path

Then type

mvn -version

You can set this in ./bash_profile to do it automatically each time you run the terminal

khmarbaise

You should change the location of the M2_HOME into the following:

set M2_HOME=C:\apache-maven-3.0.4\apache-maven

Furthermore the installation of the JDK looks more a JRE instead of JDK. For Maven you need JDK and NOT JRE.

Thanks but I am having both jdk and jre. You can see that I have given the JAVA_HOME as C:\Program Files\Java\jdk1.7.0_04. And if I give the path for M2_HOME that you have told, the cmd will not even recognize the 'mvn' command.

You change the M2_HOME as i described it will add the %M2_HOME%\bin to your path which is needed to call the mvn command.

Saif Asif

I came across a similar problem on my mac OSX. After a series of trial and error attempts I finally resolved it.

My ~/.bash_profile looked like this

export M2_HOME=/Users/xyz/maven-3.x/bin
export PATH=$PATH:$M2_HOME

and when I tried to echo M2_HOME from the terminal, it showed me the correct path but when I tried to fire any maven command like mvn clean or mvn install, it always gave the same problem

Could not find or load main class org.codehaus.plexus.classworlds.launcher.Launcher

I solved this issue by changing my M2_HOME to this

export M2_HOME=/Users/xyz/maven-3.x
export PATH=$PATH:$M2_HOME/bin

And voila ! It started working ! Just by moving the position of /bin from M2_HOME to in front of the PATH

Shaini Sinha

Just make sure you've downloaded Binary zip archive(apache-maven-3.5.0-bin.zip) instead of Source zip archive. Then add the bin directory of the created directory apache-maven-3.5.0 to the PATH environment variable.

Bharath Kumar

install binary version of maven fixes the issues

apache-maven-3.6.1-bin.zip

Ankur

I had the same issue. I have Windows xp box and when I would type mvn -version at the command line prompt I got the dreaded error message

"Exception in thread "main" java.lang.NoClassDefFoundError: org/codehaus/plexus/classworlds/launcher/Launcher"

I confirmed that my M2_HOME variable was set to the path where Maven was installed on pc and that the echo %path% confirmed that Maven was in my path.

I have been searching for a solution for hours when I stumbled on to my solution (I say my solution because I know this probably won't be the solution for everyone that is getting the same error).

I copied the path that was assigned to my M2_HOME variable. I opened a cmd window and typed cd and pasted the path I got from my M2_HOME variable. At that point I knew that the path was correct because the path was displayed in the window. At this point I entered the dir command and to my surprise, I got the error File Not Found.

I went to that path via Explorer and sure enough there were files present. I noticed that the folders were faded out, but I could access them and see the files within each folder (I have admin rights on my pc). I looked at the properties of the parent folder for Maven and saw that the Hidden box was checked. I removed the check and applied and tried my dir command again with success.

Next I tried the mvn –version command again, but this time I got back the expected results.

C:\>mvn -version
Apache Maven 3.0.3 (r1075438; 2011-02-28 11:31:09-0600)
Maven home: C:\Program Files\apache-maven-3.0.3
Java version: 1.5.0_16, vendor: Sun Microsystems Inc.
Java home: C:\Java\jdk1.5.0_16\jre
Default locale: en_US, platform encoding: Cp1252
OS name: "windows xp", version: "5.1", arch: "x86", family: "windows"

Finally I created a jar and war file and my web app ran successfully on my local Tomcat.

I hope this helps some of you out there.

Raghuram

Besides what @khmarbaise has pointed out, I think you have mistyped your JAVA_HOME. If you have installed in the default location, then there should be no "-" (hyphen) between jdk and 1.7.0_04. So it would be

JAVA_HOME C:\Program Files\Java\jdk1.7.0_04

Thanks but Unfortunately I mistyped it here only and it was same as you have told, 'without a hyphen'.

JBCP

For other people who might run into this, don't forget to check ~/.mavenrc for M2_HOME or JAVA_HOME settings.

Shendor

Try to download binary zip (for ex. Maven 3.0.5 (Binary zip)) instead of complete source in official maven site. Also make sure that command line recognizes java and javac commands. I noticed that Maven Source zip didn't include any libraries at lib folder however Binary zip had them + in boot folder it had plexus-classworlds-2.4.jar. Perhaps the problem was with the absence of these libraries. Anyway it helped me so my M2_HOME is: C:\Program Files\Java\apache-maven-3.0.5 and at PATH I put: C:\Program Files\Java\apache-maven-3.0.5\bin.

wu liang

I find this issue in my centOS is caused by "Oracle Java is replace by gcj", after change default java to "Oracle Java", the issue is resolved.

alternatives --config java

There are 2 programs which provide 'java'.

  Selection    Command
-----------------------------------------------
*  1           /usr/lib/jvm/jre-1.5.0-gcj/bin/java
 + 2           /usr/java/jdk1.7.0_67/bin/java

Hammad Hassan

It look like that you have installed Source files(Because src only comes in Source Files and we don't need it). Try to install Binary Files from there. And then set environment variables as described there. This worked for me. And I am sure it will also work for you.

Mithril

I think you download the wrong version. I meet this problem just now, no method work after searching and searching. Finally, I found that maven I downloaded is Source zip archive. After I change to Binary zip archive, everything go to be fine.

I was just about to post this. This is exactly the problem I faced. If only I had read your answer before it would have saved me 30 minutes.

vinoth kumar

Me too faced the similar issue. But in my case I used apache-maven-3.3.3-src folder in path variables. Later I corrected those with correct path of folder apache-maven-3.3.3-bin. This resolved the issue. Am not telling that is the same error reported here but this way also you can get this error and rectify it. That is what I am trying to say here.

dytori

Exactly the same error may appear even with correct environment variable settings, if you copy ONLY bin directory to the installation directory. It make which work finely, and novices get stuck.

peterh

Next to the maybe useful, but maybe too symptomatic answers, here is one which tries to help to find the cause of the problem.

Maven is a command-line java tool. That means, it is not a standalone binary, it is a collection of java .jars, interpreted by a jvm (java.exe on windows, java on linux).

The mvn command, is a script. On windows, it is a script called mvn.cmd and on linux, it is a shell script. Thus, if you write: mvn install, what will happen:

a command interpreter (/bin/sh or cmd.exe) is called for the actual invoking script this script sets the needed environment variables and finally, it calls a java interpreter with the the required classpath which contain the maven functionality.

The problem is with (2). Fortunately, this script is simply, very simple. For a java programmer it shouldn't be a big trouble to debug a script around 20 lines, even if it is a little bit alien language.

On linux, you can debug shellscripts giving the -x flag to your shell interpreter (which is most probably bash). On windows, you have to find some other way to debug a cmd.exe script. So, instead of mvn install, give the command bash -x mvn install.

The result be like:

+ '[' -z '' ']'
+ '[' -f /etc/mavenrc ']'
+ '[' -f /home/picsa/.mavenrc ']'
+ cygwin=true
+ darwin=false

...not so many things...

+ MAVEN_PROJECTBASEDIR='C:\peter\bin'
+ export MAVEN_PROJECTBASEDIR
+ MAVEN_CMD_LINE_ARGS=' '
+ export MAVEN_CMD_LINE_ARGS
+ exec '/cygdrive/c/Program Files/Java/jdk1.8.0_66/bin/java' -classpath 'C:\peter/boot/plexus-classworlds-*.jar' '-Dclassworlds.conf=C:\peter/bin/m2.conf' '-Dmaven.home=C:\peter' '-Dmaven.multiModuleProjectDirectory=C:\peter\bin' org.codehaus.plexus.classworlds.launcher.Launcher
Fehler: Hauptklasse org.codehaus.plexus.classworlds.launcher.Launcher konnte nicht gefunden oder geladen werden

At the end, you can easily test, which environment variable gone bad, and you can very easily fix your script (or set it what is needed).

I appreciate this answer.. For me it was reusing some "dot files" across systems without customizing, which was messing up the "CLASSWORLDS_JAR=build-classpath plexus-classworlds" call. The point is there's any number of things you mess up and yeah, you just have to bite the bullet and run set -x and debug.

Christian Hujer

I had this problem when I used Maven 3.5.4 on OpenJDK 11 on Ubuntu. The OpenJDK 11 on Ubuntu is actually still a JDK10:

$ ls -al /etc/alternatives/java
lrwxrwxrwx 1 root root 43 Aug 24 04:54 /etc/alternatives/java -> /usr/lib/jvm/java-11-openjdk-amd64/bin/java
$ java --version
openjdk 10.0.2 2018-07-17
OpenJDK Runtime Environment (build 10.0.2+13-Ubuntu-1ubuntu0.18.04.3)
OpenJDK 64-Bit Server VM (build 10.0.2+13-Ubuntu-1ubuntu0.18.04.3, mixed mode)

I installed OpenJDK from Oracle into /opt/jdk-11.0.1 and run Maven like this:

JAVA_HOME=/opt/jdk-11.0.1 mvn

It now works like a charm.

Coolius

I had a problem with surefire plugin itself. Going back to version 2.6 worked for me. Version 2.18/20/22.1 gave me the error. Now I tried version 3.0.0-M1 of surefire plugin and it works.

So something is wrong in surefire plgin between version 2.6 and 3.0.0. I assume there is something hardcoded as default which should not.

membersound

For me, funny as it sounds, it helped just restarting eclipse...

Aberaitius

This worked for me:

Remove all Mavin references in Environment Variables Download the Binary from mavin Unzip it to where you'd like ex: C:\apache-maven-3.6.0 Go to Environment variables and add to System variable path "C:\apache-maven-3.6.0\bin" start command prompt as Administrator check version with: mvn -v

CMD Result:

Apache Maven 3.6.0 (97c98ec64a1fdfee7767ce5ffb20918da4f719f3; 2018-10-24T20:41:47+02:00) Maven home: C:\apache-maven-3.6.0\bin..

Venkata Rajeev Mandava

I also faced the following Error in my system (Mac)

Error: Could not find or load main class org.codehaus.plexus.classworlds.launcher.Launcher

After doing some random browsing, I came across the link "http://maven.apache.org/install.html" that says "JAVA_HOME" should be set to "/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/jre".

When I changed "JAVA_HOME" as stated above in ".bash_profile", "mvn" command started working but "javac -version" command stopped working.

When I typed "javac -version" command, I got the following error

Unable to locate an executable at "/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/jre/bin/javac" (-1)

Hence I rolled back my "JAVA_HOME" to "/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home" in ".bash_profile" and added the following line at the top in "mvn" script

export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/jre

Now both "mvn" and "javac" commands worked properly, but after careful observation of the mvn script, I could not make the difference between the following commands

/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/bin/java -classpath /Users/venkatarajeevmandava/Documents/Maven/apache-maven-3.6.1/boot/plexus-classworlds-2.6.0.jar -Dclassworlds.conf=/Users/venkatarajeevmandava/Documents/Maven/apache-maven-3.6.1/bin/m2.conf -Dmaven.home=/Users/venkatarajeevmandava/Documents/Maven/apache-maven-3.6.1 -Dlibrary.jansi.path=/Users/venkatarajeevmandava/Documents/Maven/apache-maven-3.6.1/lib/jansi-native -Dmaven.multiModuleProjectDirectory=/Users/venkatarajeevmandava/Documents/Maven/apache-maven-3.6.1/bin org.codehaus.plexus.classworlds.launcher.Launcher

/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/jre/bin/java -classpath /Users/venkatarajeevmandava/Documents/Maven/apache-maven-3.6.1/boot/plexus-classworlds-2.6.0.jar -Dclassworlds.conf=/Users/venkatarajeevmandava/Documents/Maven/apache-maven-3.6.1/bin/m2.conf -Dmaven.home=/Users/venkatarajeevmandava/Documents/Maven/apache-maven-3.6.1 -Dlibrary.jansi.path=/Users/venkatarajeevmandava/Documents/Maven/apache-maven-3.6.1/lib/jansi-native -Dmaven.multiModuleProjectDirectory=/Users/venkatarajeevmandava/Documents/Maven/apache-maven-3.6.1/bin org.codehaus.plexus.classworlds.launcher.Launcher

In the above the first command caused the following error

Error: Could not find or load main class org.codehaus.plexus.classworlds.launcher.Launcher

while the second command worked fine. Please Note that both the above paths have "java" command while one is from "jre" the other is from "jdk"

Other global variables are as following in ".bash_profile"

export M2_HOME=/Users/venkatarajeevmandava/Documents/Maven/apache-maven-3.6.1

export PATH=$PATH:$M2_HOME/bin

Kshitij Kohli

Was able to solve this issue by deleting the downloaded maven in my machine ( /Users/kkohli/Desktop/Personal/Code/Java/apache-maven-3.6.3 ) and re-downloading the binary version from the apache site. Did not modify any other bashprofile file etc ( My M2_HOME, JAVA_HOME etc are set inside my bashprofile)

Follow WeChat

Success story sharing

Want to stay one step ahead of the latest teleworks?

Subscribe Now

相似问题

What does "Could not find or load main class" mean?

Maven error: Could not find or load main class org.codehaus.plexus.classworlds.launcher.Launcher

Follow WeChat

Want to stay one step ahead of the latest teleworks?

相似问题

Platform

Support

Links

Contact US