jnetpcap library unable to build on ubuntu 12.04

jnetpcap library unable to build on ubuntu 12.04 - java

I am trying to install JNetPcap and followed the instructions given at here. At step 12, I am unable to run the ant command and i see the error
Error: JAVA_HOME is not defined correctly.
We cannot execute /usr/lib/jvm/java-6-sun/bin/java
As I am able to run Java classes from eclipse or from command line I don't think if it's a problem with JAVA_HOME.
echo $PATH shows
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/lib/jvm/java-6-sun/bin
Kindly let me know if am missing something here.
thanks in advance

Neither running java from the command line or running eclipse will require JAVA_HOME to be set. However, the build procedure you are trying to use ant, and ant often does require JAVA_HOME to be set appropriately. (It actually depends on the version of ant that you are using. The use of JAVA_HOME is typically in the wrapper script for ant.)
Just set it.
JAVA_HOME should probably be set to /usr/lib/jvm/java-6-sun ... based on what you gave said PATH to.
However, it is also possible that the problem is that your PATH is incorrect. Or that you have (somehow) managed to get the owner/group/permissions on your Java install incorrect, such that the java command isn't executable.
Check that running java -version displays the installed Java version.
Repeat with /usr/lib/jvm/java-6-sun/bin/java -version.

Related

Purpose of setting PATH variable for Java

I'm a complete noob and have been trying to set my mac to learn Java. I have installed JDK 10.0.1 and eclipse oxygen. I also successfully edited the JAVA_HOME variable to point to my jdk location using this:
Setting JAVA_HOME environment variable on MAC OSX 10.9
So far so good, I was able to run simple programs both on eclipse and on terminal ( was having trouble for a while because I couldn't run "HelloWorld" from terminal as it was under a separate package) after using the top answer from Running java in package from command line
However my friend later told me that if I wanted to run java programs from terminal, I'd need to edit PATH variable as it was where the os looks for executables. A lot of websites mentioned editing PATH as well. I ran echo $PATH and terminal outputted /usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/opt/X11/bin.
So I'm really confused that if I haven't edit PATH, then why am i able to run commands like java or javac from terminal? The /usr/bin folder has java javac javadoc etc aliases inside it, could that be the reason?

mvn could not find or load main class org.codehaus.plexus.classworlds.launcher.launcher [duplicate]

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 I'm still not able to get to it. What I might be missing in this whole thing?

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

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 was having this same problem and was able to resolve it by carefully redoing the Environment Variables:
M2_HOME
M2
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]

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

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 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.

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)

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.

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)

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

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.

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

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.

install binary version of maven fixes the issues
apache-maven-3.6.1-bin.zip

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.

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

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

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.

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

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.

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.

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.

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.

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 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.

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.

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

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..

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

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)

Ant is unable to find a javac compiler

I am trying to build some binaries of an application. When i am trying to make the build, I am getting this:
BUILD FAILED
/home/.../ant-build.xml:84: Unable to find a javac compiler;
com.sun.tools.javac.Main is not on the classpath.
Perhaps JAVA_HOME does not point to the JDK.
It is currently set to "/usr/lib/jvm/java-8-openjdk-amd64/jre"
The application requires java 7, and i have it installed but i had it along java 8. The build requires for tools.jar which is located in java 7 only, therefore after several attempts i uninstalled java 8. However, when I am trying make again, i get the same error, even though i don't have java8 installed at all!
I set the JAVA_HOME properly:
$ echo $JAVA_HOME
/usr/lib/jvm/java-7-openjdk-amd64/
I doubt i need the path but i set that one up just in case as well :
$ echo $PATH
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/usr/lib/jvm/java-7-openjdk-amd64/bin
I'm running out of ideas here :P any help would be appreciated.
Also something maybe important, I had to add the repo manually to get java-7 otherwise it wasnt able to locate the package. Thats when i got double jdk-s.

I guess you are calling the JAVAC command from any other source/tool like Jenkins/Bamboo/Teamcity. Make sure you have set the environment variable of that tool. usually it lies in the manage tool option.
I was facing same issue while using Jenkins.If you don't set up an environment variable in tool from which you are making a call it take your
"/usr/lib/jvm/java-8-openjdk-amd64/jre" so go and set the the env variable JAVA_HOME of you tools. attaching screen shot of Jenkins issue. Go to Manage Jenkins -->configure system --> environment variables and set you java_home path.
Cheers

I just encountered the same situation.
That is because JAVA_HOME is not correctly set in sudo environment.
I added export JAVA_HOME=/path/to in /root/.bashrc, and eventually it was built right.

It seems that you are using javac of java8 with JAVA_HOME or CLASS_PATH pointing to java7.
You can use which java to check that.
export JAVA_HOME=/lib/jvm/java-7-openjdk-amd64
export export ${PATH}=${JAVA_HOME}:/bin:${PATH}`

JAVA_HOME error in Titanium Studio on Linux Mint

I will try and keep this as concise as possible since I need to get this figured out quickly. Back when I setup Titanium Studio 2.1.1.201207271312 on Linux Mint 13 64-bit system, I had all kinds of problems installing a version of Java Titanium liked. In the end I Think I used the instructions here to get it working.
Now all these months later when I try to compile an app for Google Play I get this dreaded error:
[ERROR] Program launch failed. Unable to locate Java VM. Please set JAVA_HOMenvironment variable.
[ERROR] Unabled to prepare JavaScript for packaging. Error code 4.
Checking the java alteranatives on my system I get this:
'update-alternatives --query java
Link: java
Status: auto
Best: /usr/lib/jvm/java-6-sun/jre/bin/java
Value: /usr/lib/jvm/java-6-sun/jre/bin/java
Alternative: /usr/lib/jvm/java-6-sun/jre/bin/java
Priority: 63
Slaves:
java.1.gz /usr/lib/jvm/java-6-sun/jre/man/man1/java.1.gz
Alternative: /usr/lib/jvm/java-7-oracle/bin/java
Priority: 1
Slaves:
java.1.gz /usr/lib/jvm/java-7-oracle/man/man1/java.1.gz
I have the following set in my .profile
export JAVA_HOME=/usr/lib/jvm/java-6-sun/jre/bin/java
export PATH=$PATH:/usr/lib/jvm/java-6-sun/jre/bin/java
But still I get the error in Titanium. I have tried numerous different variations of my .profile file, but with no luck.
I really need to work this out quickly. Does anyone have any ideas?
EDIT: Solved
I seem to have worked the proper paths, here is how my .profile now reads:
JAVA_HOME=/usr/lib/jvm/java-6-sun/jre
export JAVA_HOME
PATH=$PATH:/usr/lib/jvm/java-6-sun
export PATH

.profile is usually processed by sh, while .bash_profile is processed by bash (and instead of .profile when present). Try following sh compatible format (which has bitten me before when mucking with .profile files):
JAVA_HOME=/usr/lib/jvm/java-6-sun
export JAVA_HOME
PATH=$PATH:/usr/lib/jvm/java-6-sun/bin:/usr/lib/jvm/java-6-sun/jre/bin
export PATH
I Corrected to what I usually use, I was just echoing your values, but I should have been more careful. I usually have JDK and JAVA_HOME is supposed to be the base for it and then I add bin for both JDK and JRE. If you compiling then you may need the JDK and not just the JRE.

I seem to have worked out the proper paths, here is how my .profile now reads:
JAVA_HOME=/usr/lib/jvm/java-6-sun/jre
export JAVA_HOME
PATH=$PATH:/usr/lib/jvm/java-6-sun
export PATH

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

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 I'm still not able to get to it. What I might be missing in this whole thing?

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

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 was having this same problem and was able to resolve it by carefully redoing the Environment Variables:
M2_HOME
M2
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]

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

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 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.

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)

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.

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)

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

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.

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

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.

install binary version of maven fixes the issues
apache-maven-3.6.1-bin.zip

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

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

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.

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

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.

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.

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.

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.

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 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.

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.

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

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..

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

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)

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