java.lang.NoClassDefFoundError in a jar

[Alejandro Barrero]

I have an application in Eclipse that runs fine in Eclipse. I have been testing it as a jar file for some time, but today I got the error java.lang.NoClassDefFoundError. After browsing the Internet I have found many discussions but no solution; I have also read answers to similar questions in this forum. Please tell me what do I have to look inside the jar file or what log do I have to look into.

[Alejandro Barrero]

Further clarification. The error I receive when executing a batch file with contents "java -jar paperless.jar" is "java.lang.NoClassDefFoundError: org/objenesis/Objenesis"; however, after I unzipped the jar file the file ".classpath" contains:

<?xml version="1.0" encoding="UTF-8"?>
<classpath>
	<classpathentry kind="src" path="src"/>
	<classpathentry kind="lib" path="lib/swing-layout-1.0.3.jar"/>
	<classpathentry kind="lib" path="lib/AbsoluteLayout.jar"/>
	<classpathentry kind="con" path="org.eclipse.jdt.junit.JUNIT_CONTAINER/4"/>
	<classpathentry kind="lib" path="C:/Workspaces/Jars-Libraries/cloning-1.7.9.jar"/>
	<classpathentry kind="lib" path="C:/Workspaces/Jars-Libraries/commons-lang-2.6.jar"/>
	<classpathentry kind="lib" path="C:/Workspaces/Jars-Libraries/commons-logging-1.1.1.jar"/>
	<classpathentry kind="lib" path="C:/Workspaces/Jars-Libraries/hsqldb.jar"/>
	<classpathentry kind="lib" path="C:/Workspaces/Jars-Libraries/jackcess-2.0.8.jar"/>
	<classpathentry kind="lib" path="C:/Workspaces/Jars-Libraries/mailapi.jar"/>
	<classpathentry kind="lib" path="C:/Workspaces/Jars-Libraries/ucanaccess-4.0.4.jar"/>
	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/jre1.8.0_161">
		<attributes>
			<attribute name="owner.project.facets" value="java"/>
		</attributes>
	</classpathentry>
	<classpathentry kind="lib" path="C:/Workspaces/Eclipse/Jars-Libraries/objenesis-2.6.jar"/>
	<classpathentry kind="output" path="bin"/>
</classpath>

After unzipping objenesis-2.6.jar I found out that the class is there.

[Rob Spoor]

.classpath only works inside Eclipse. When you run your JAR outside of it the file has no meaning at all. Instead you should use META-INF/MANIFEST.MF to add a Class-Path entry: https://docs.oracle.com/javase/tutorial/deployment/jar/downman.html. Note that these dependencies cannot be located inside your JAR file, because the class loader won't be able to find them there. The best is to use a relative path, and ship the JARs with your own JAR inside a ZIP file. Make sure that you are allowed to though, some libraries may prohibit this.

[Alejandro Barrero]

Thank you for your prompt reply. I have no intention of using the classpath; I only posted what is in the jar file. The jar file is created by Eclipse and until yesterday it was working fine. If worse comes to worse, I am willing to modify the jar file, but someone has to tell me how.

[Lakshman Arun]

Few questions

1. How you run the jar file, using command prompt or using IDE
2. If run thru command prompt, can you whats the classpath variable points to.
3. For which class it is throwing NoClassDefFoundError.

[Alejandro Barrero]

To answer all the questions; this is what I get running the jar file:

C:\Workspaces\JAR Files>java -jar paperless.jar
java.lang.NoClassDefFoundError: org/objenesis/Objenesis
       at com.paperless.main.PropertiesDialog.dbFileOk(PropertiesDialog.java:184)

As I mentioned in a previous response, org/objenesis/Objenesis class shows in the jar file after I unzipped it.

[Henry Wong]

Alejandro Barrero wrote:
As I mentioned in a previous response, org/objenesis/Objenesis class shows in the jar file after I unzipped it.

Your previous response mentioned that you unzipped a different jar file ... and Rob mentioned that you need to modify the manifest to point to that different jar file. Are you now saying that the class exists in the paperless jar file that is executed?

Henry

[Lakshman Arun]

How you are referring Objenesis , with fully package name or just Objenesis inside your PropertyFile class

[Lakshman Arun]

Typo PropertiesDialog class

[Alejandro Barrero]

Thanks to all; I solved the problem by unzipping objenesis-1.2.jar and added the code to the project.

[Dave Tolls]

That's not really a solaution, it's more a bit of sticky tape over the problem.