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NoClassDefFoundError when running Jar

I have this Problem. When i run my code in Intellij it works fine, but if i do an artifact and build the jar, it doesnt work. I think its caused by an extern library. Heres my output:
Exception in thread "main" java.lang.NoClassDefFoundError: com/mindfusion/scheduling/Calendar
at GUI.<init>(GUI.java:75)
at Logfiles.main(Logfiles.java:13)
Caused by: java.lang.ClassNotFoundException: com.mindfusion.scheduling.Calendar
at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:606)
at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:168)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:522)
... 2 more
I know which Class it is but i dont know how to solve the Problem. Im really just a beginner. Could you please help me and explain it simple. Thank you
Edit:
After i build the artifact with extracted Libraries this Error comes : Error: A JNI error has occurred, please check your installation and try again
Exception in thread "main" java.lang.SecurityException: Invalid signature file digest for Manifest main attributes

This error simply means the class file is not present in the jar.
One possible solution is you can download jd-gui which is used to look at jars. You can use this to check if the class is present.
Another solution is you can grep search the class in the jar with this simple command.
grep -l "<class-name>" <jar-name>.jar
if the class is not present in the jar file. you can add the class using jar command.
jar -cvf <jar-absolute-location> <class-path>
eg : jar -cvf GUI.jar com.mindfusion.scheduling.Calendar

The easiest way to understand this issue, it to read the Javadoc for that class. From the Javadoc:
Thrown if the Java Virtual Machine or a ClassLoader instance tries to
load in the definition of a class (as part of a normal method call or
as part of creating a new instance using the new expression) and no
definition of the class could be found.
The searched-for class definition existed when the currently executing class was compiled,
but the definition can no longer be found.
That means that NoClassDefFoundError can be thrown when that particular class is present during compile time but somehow not available during runtime. This could be due to missing JAR file, permission issues, or incorrect classpath on runtime.
Normally I see these issues when developers neglect to define the classpath for used libraries. They forget that your IDE has its own file defining the classpath (i.e. Eclipse has the .classpath file) so running the application from the IDE works fine (class is present during compile time), but after the application is compiled and the classpath is not defined in the machine hosting the application, NoClassDefFoundError is thrown (class "missing" at runtime).
My suggestion is figured out first if the classpath is correct. More times than none, this is the issue. If the classpath is correct, make sure all permissions are set correctly.

Class not found even when in Jar in the classpath

I am trying to deploy an application that is using Jackson, JUnit, and Commons-IO. I have the following Jars in my application's classpath:
commons-io-2.4.jar
jackson-databind-2.7.0.jar
jackson-annotations-2.7.0.jar
log4j-api-2.4.1.jar
wsdiscovery-0.2.jar
jackson-core-2.7.0.jar
log4j-core-2.4.1.jar
This application works within my development environment, and I have deployed all of the above Jars with the main application jar. I can run the application without problems, but every time I try to use it I get the following failure:
Exception in thread "main" java.lang.NoClassDefFoundError: com/fasterxml/jackson/databind/ObjectMapper
at com.oncam.hware.app.OnvifApp.formatOutput(OnvifApp.java:356)
at com.oncam.hware.app.OnvifApp.dispatchCommand(OnvifApp.java:271)
at com.oncam.hware.app.OnvifApp.loopSocket(OnvifApp.java:130)
at com.oncam.hware.app.OnvifApp.useSocket(OnvifApp.java:216)
at com.oncam.hware.app.OnvifApp.main(OnvifApp.java:473)
Caused by: java.lang.ClassNotFoundException: com.fasterxml.jackson.databind.ObjectMapper
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
... 5 more
The ObjectMapper class is in the jackson-databind-2.7.0.jar file. Furthermore, I have no problems accessing the classes in the other jar files (including the JUnit jars!). For some reason, it is as if the classloader is loading every Jar except jackson-databind-2.7.0.jar.
Does anyone know what is causing this and how I can fix it?
Someone please advise...

I figured out what was wrong.
It turns out that the environment I am using (Eclipse!) does not properly update the manifest file when you export your code to a JAR file. Without the proper manifest entries, the application cannot "find" the dependent jar files.
This is, in my opinion, a serious oversight on the part of the Eclipse folks -- especially when you have an application that depends on a lot of jar files. In order to make my application run, I had the following choices:
Create a script that runs the jvm and has a list of parameters pointing to every needed jar file, or:
2: Manually enter each required jar file into the Manifest file
To my knowledge, there is no way to automatically update the manifest file. This is a serious PITA (Pain In The A**)...
Anyway, sorry for bothering people about this problem. Hopefully, posting this answer will help others avoid similar problems...

Shared jar and noclassdeffound java

Im running a debian java server that needs to send and receive objects of type EventObject and PostObject (e.g serializable). These have been placed in a .jar file SharedModels.jar and are used both in client and server.
On the windows installation (Eclipse), using
import Models.EventObject;
import Models.PostObject;
works fine (including external Jar through Eclipse).
It compiles fine, but when the method is called on the server , the server doesn't recognize the class anymore. This is the output:
Exception in thread "Thread-0" java.lang.NoClassDefFoundError: Models/PostObject
at server.Database.getPosts(Database.java:101)
at server.ServerThread.run(ServerThread.java:47)
Caused by: java.lang.ClassNotFoundException: Models.PostObject
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)
... 2 more
I've understood this is because JVM does recognize the class at compiletime but not during runtime.. OR something is wrong with classpath. Does the name of the actual .jar need to have any naming to fid the package contained within? What do I need to do to fix this?

If your Models/PostObject is a class from some jar, then make sure that the class is included in exported jar/war (simply open it with tool like 7zip and manually confirm that the needed class is there).
How to create a jar with external libraries included in Eclipse?

This is thrown when at compile time the required classes are present , but at run time the classes are changed or removed or class's static initializes threw exceptions. It means the class which is getting loaded is present in classpath , but one of the classes which are required by this class , are either removed or failed to load by compiler .So you should see the classes which are dependent on this class

When executing JAR, get ExceptionInInitializerError: version.properties not found

I've been writing a small project in Eclipse which runs perfectly within the IDE. Then I've build a runnable .jar file through Eclipse (which should include every dependency library inside the jar itself).
I use 3 library in my project:
derby.jar
qtjambi-4.7.1.jar
qtjambi-win32-msvc2008-4.7.1.jar
Then I use this command (in windows):
java -jar prova.jar
And I get this:
Connected to database
Exception in thread "main" java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.eclipse.jdt.internal.jarinjarloader.JarRsrcLoader.main(JarRsrcLoa
der.java:58)
Caused by: java.lang.ExceptionInInitializerError: version.properties not found!
at com.trolltech.qt.Utilities.<clinit>(Unknown Source)
at com.trolltech.qt.QtJambi_LibraryInitializer.<clinit>(Unknown Source)
at com.trolltech.qt.QtJambiObject.<clinit>(Unknown Source)
at WAAAGH.main(WAAAGH.java:52)
... 5 more
As you can see the derby.jar is working as expected ("Connected to database"), but there's an error with Qt-Jambi that I can't understand. Any idea?
EDIT: WAAAGH is the class containing the main method, line 52 consists in:
QApplication.initialize(args);

How is QtJambiObject getting loaded? Have you packeged it inside your prova.jar? The missing file version.properties should be part of the same jar at top level (not in any subdir). It seems you have not packaged it inside prova.jar at top level. See this for explanation of how it is loaded.
You might be better off specifying all jars and main class on command line:
java -classpath prova.jar;derby.jar;qtjambi-4.7.1.jar;qtjambi-win32-msvc2008-4.7.1.jar <your main class>
replace ; with : if you are running on *nix

FWIW the location of version.properties has recently been changed to be inside the package namespace of the bundles com/trolltech/qt/version.properties. The old location was a poor design choice and that has now been corrected. The issue is that if you have another JAR in your classpath that also has a toplevel file then the ClassLoader is entitled to think that the JAR with that file is authorative for the package and it does not need to search another JAR for the file. A package is a minimum deployable unit in Java, only specialist ClassLoaders (such as those use in OSGi) have features to work around this part of the Java design.
Usually your toplevel (application JAR) will be first in the list and I bet in that JAR you have one or more files like /log4j.properties /commons-logging.properties etc... it is because one or more file exists it then masks (hides) the file in the qtjambi-X.Y.Z.jar from being seen at runtime. Which is why the problem might not exist when you test a certain scenario but then appear when you try another (when you changed ClassPath in some way).
My commit to the project at http://qt.gitorious.org/qt-jambi/qtjambi-community/commit/f18ce5da3e30b43424bf94e49adf8c4cac0d9862 better explains in code the very recent change to make life better.
It should never have been the case that you have to copy the version.properties file from the QtJambi redistributable JARs into some other part of the Class Path (like the toplevel project prova.jar in your case) this is a bug that has been corrected for the next release. It is the long term intention to remove the need for the file completely and I am 80% there with that goal, as part of that work making multiple native JARs co-exist in the same Class Path will greatly simplify deployment and getting started guides; as well as making them play with OSGi and Eclipse nicely out-the-box.
However no releases have been made yet to include this change but I am very close (within 30 days of doing so for Qt 4.7.4).
Open Source plug alert: Please consider joining the mailing list at http://lists.qt.nokia.com/pipermail/qt-jambi-interest/ from http://lists.qt.nokia.com/mailman/listinfo for announcements.

"ClassFormatError: Incompatible magic value" when trying to run Java jar file

I typed in "java -jar ShowTime.jar", and got this error message:
Exception in thread "main" java.lang.ClassFormatError: Incompatible magic value 1347093252 in class file ShowTime
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(ClassLoader.java:632)
at java.lang.ClassLoader.defineClass(ClassLoader.java:616)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:283)
at java.net.URLClassLoader.access$000(URLClassLoader.java:58)
at java.net.URLClassLoader$1.run(URLClassLoader.java:197)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
How should I fix this?
P.S. I have a mac.

A Java class should start with the magic (hex) value 0xCAFEBABE (neat huh). Your value 1347093252 is 0x504B0304 in hex, which happens to be the magic value for a ZIP file (first 2 bytes in ASCII are PK for Phil Katz, creator of the ZIP format). A jar is also a zipfile btw, so probably your jar is pretty much corrupt. Try rebuilding the entire project.

That usually means that you compiled the jar for a newer version of java than you ran it with. Check to see if you are using the same version of java to compile and run. If that doesn't fix the problem, please provide more info such as the compiler command and the output of java -version.

It means your application is using a jar file which is complied in a specific format in some other system. Now when you are trying to use the project in other system, the other system is not able to decode the jar, as each system generated a specific key to bundle the project.
Remote debug id the best way to find the issue that which jar is not in the proper format. Run the command in comment prompt for remote debug
java -agentlib:jdwp=transport=dt_socket,server=y,address=8001,suspend=n (command and parameter to run you jar)
what you need is, find the jar file and replace with another jar (may be a freshly downloaded one or if you teammate has the jar. Use it.)
The error i was getting because my project way having dependency with another project ABC, and ABC was using a generic jar. But project ABC was bundled with the magic key. I have replaced the jar used by ABC with a downloaded jar.

I got this error when the main class name of my jar was not identical to its filename.
For example, the main class of the jar was named Foo.java, and inside it I had public class Bar { ... } instead of public class Foo { ... }
It is probably not the most general answer, but making the file name and the class name identical solved this issue for me.