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Why occurs a java.lang.NoClassDefFoundError when I use args4j in a batch built by mvn:assembly

For various experimentations, I take care of a java project in github.
After the Maven build, the program runs with a script bat.
Now I opened a branch because I would use the library args4j to parsing the arguments.
The build works fine, the jars exist in the directory lib, but when I run I have this stacktrace of Exception
Exception in thread "main" java.lang.NoClassDefFoundError:
org/kohsuke/args4j/CmdLineException
at java.lang.Class.getDeclaredMethods0(Native Method)
at java.lang.Class.privateGetDeclaredMethods(Class.java:2625)
at java.lang.Class.getMethod0(Class.java:2866)
at java.lang.Class.getMethod(Class.java:1676)
at sun.launcher.LauncherHelper.getMainMethod(LauncherHelper.java:494)
at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:486)
Caused by: java.lang.ClassNotFoundException:
org.kohsuke.args4j.CmdLineException
at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
... 6 more
in bat I configured the classpath so that the args4j jar in in lib: this are the instructions of bat script
SET JAVA_DIR=C:\Program Files\Java\jdk1.7.0_80\bin\
>CUT
"%JAVA_DIR%\java" -jar ".\lib\buildCSS-1.0.jar" -cp ".\lib\" -conf "./conf/environment.properties"
I don't understand the deal of java.lang.NoClassDefFoundError. The jar are present and linked by -cp option
Do you have any idea (and solution), please?

You cannot combine -jar and -cp arguments on the command line. If the java command sees -jar it treats everything after the jarfile name as application arguments, AND it ignores any earlier classpath arguments.
You have two choices:
Use -cp, include the main JAR in the classpath, and put the full class name for the main class on the command line.
Use -jar, and add a "Class-Path" attribute to the main JAR's manifest file listing all of the dependencies.
References:
The java command page - explains -jar versus -cp
The JAR file specification - explains the "Class-Path" attribute
Note: since you are building the JAR file using Maven, there are other options; for example
Use the "Shade" plugin to create an executable "uber-jar" containing all of the dependencies in a single JAR.

Hadoop MapReduce ClassNotFoundException Error

I have extracted a jar from a Maven project that runs the MapReduce job. However, I keep receiving the error "java.lang.ClassNotFoundException". The things that I have tried to use to repair this is:
Configured the classpath
Tried doing job.setJar(.jar)
Attempted job.setJarbyClass(.class)
Changing JobConf path file
Caress Hadoop and tell it everything is going to be okay
I extracted the jar file from Maven and transferred it to a Linux server, and running it from there.
The full error message is:
Exception in thread "main" java.lang.ClassNotFoundException: BLAMapAttempt2
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:348)
at org.apache.hadoop.util.RunJar.run(RunJar.java:214)
at org.apache.hadoop.util.RunJar.main(RunJar.java:136)
If there is any missing information needed to answer this question, please let me know, and thank you for reading.

When exporting the jar out of Eclipse, I unchecked "classpath" because I was not running it locally. This fixed my error.

MongoDB with java Exception in thread "main" java.lang.NoClassDefFoundError: org/bson/conversions/Bson

When I execute mycode from intelliJ Idea it works fine but when I run the jar on my server it throws the below error. I am using 'org.mongodb:mongodb-driver:3.4.1' version.
Exception in thread "main" java.lang.NoClassDefFoundError: org/bson/conversions/Bson
at com.myapp.server.mongo.MongoDbHandler.prepareMongoDb(MongoDbHandler.java:68)
at com.myapp.server.mongo.MongoDbHandler.<init>(MongoDbHandler.java:22)
at com.myapp.server.Client.main(Client.java:167)
Caused by: java.lang.ClassNotFoundException: org.bson.conversions.Bson
at java.net.URLClassLoader$1.run(URLClassLoader.java:372)
at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:360)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
... 3 more

I know its an old thread and its just for those who have the similar issues. Few days back I was also facing the same issue with same error trace while running the jar by command line.After rechecking the code found that
It was not a problem of the jar version but its problem of the packaging of the
jar
After packing the jar with all proper dependencies will solve this issue.
I have used
maven-assembly-plugin
for packaging and its works.
.

If I had to guess you need to get yourself whatever BSON library you're using; I wouldn't say that Mongo is your problem.
key line here is:
"Caused by: java.lang.ClassNotFoundException: org.bson.conversions.Bson"
So it's saying that it's not finding that particular class, I would look in IntelliJ and see what BSON library it is, then put it in your build directory (or java lib) on your server.

java.lang.ClassNotFoundException when trying to run camus

I downloaded the confluent package which includes camus jars and I followed the instructions online enter link description here.
Hadoop is properly setup (meaning I can use hadoop fs -ls commands and other hadoop jar commands). However, when i tried to run
hadoop jar confluent-camus-1.0.jar com.linkedin.camus.etl.kafka.CamusJob
I got "main" classNotFound error
Exception in thread "main" java.lang.ClassNotFoundException: com.linkedin.camus.
etl.kafka.CamusJob
at java.net.URLClassLoader$1.run(URLClassLoader.java:372)
at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:360)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:344)
at org.apache.hadoop.util.RunJar.main(RunJar.java:205)
The the path to the "confluent-camus-1.0.jar" is correct (right under the folder). I didn't start the kafka service, just to try to run it.
Anyone got similar problems?
Thanks.

You should try to inspect your jar file:
jar tvf confluent-camus-1.0.jar | grep com.linkedin.camus.etl.kafka.CamusJob
If you do not find this class, try to find it in other jar, which generated by camus.
After you should add target jar with
hadoop jar confluent-camus-1.0.jar com.linkedin.camus.etl.kafka.CamusJob -libjars {JAR_NAME}

Hadoop external jars

I am trying to run a hadoop job on a server. The version is 0.20.2.
I have a big amount of jars, I am running:
hadoop jar GenData.jar -libjars /path/jar1,path/jar2,...
I am getting the error below even if the corresponding classes are inside the jars:
Exception in thread "main" java.lang.NoClassDefFoundError:
org/apache/avro/mapreduce/AvroKeyInputFormat at
GenerateTrainningData.main(GenerateTrainningData.java:256) at
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606) at
org.apache.hadoop.util.RunJar.main(RunJar.java:197) Caused by:
java.lang.ClassNotFoundException:
org.apache.avro.mapreduce.AvroKeyInputFormat at
java.net.URLClassLoader$1.run(URLClassLoader.java:366) at
java.net.URLClassLoader$1.run(URLClassLoader.java:355) at
java.security.AccessController.doPrivileged(Native Method) at
java.net.URLClassLoader.findClass(URLClassLoader.java:354) at
java.lang.ClassLoader.loadClass(ClassLoader.java:425) at
java.lang.ClassLoader.loadClass(ClassLoader.java:358)

Looks like you are getting this exception from Hadoop client side, Mapreduce driver code execution happens in Client JVM. In hadoop -libjars is a generic option which is used for adding dependent jars to mapper/reducer. In your case for adding Jars to Client set you may set the following environment variable,before executing the hadoop command.
export HADOOP_CLASSPATH=<PATH_to_jar>/Jar1:<PATH_to_jar>/Jar2;
(colon ":" can be used for specifying more than 1 jars, In your case you may add the Jar that contains the class org.apache.avro.mapreduce.AvroKeyInputFormat).
New edits
Here first of all you need to find the jar containing the class org.apache.avro.mapreduce.AvroKeyInputFormat. You can find the class inside the jar avro-mapred*.jar (Get the compatible version of avro-mapred-version.jar from internet ) include the same in your classpath using the above command.

You are missing avro-mapred dependency.