Running JUnit Tests from Eclipse gives ClassNotFound Error

Question

I am trying to run JUnit tests from Eclipse but while running these tests, I am getting ClassNotFound Exception

Complete Stack Trace follows:

java.lang.NoClassDefFoundError: of Caused by: java.lang.ClassNotFoundException: of at java.net.URLClassLoader$1.run(URLClassLoader.java:202) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:190) at java.lang.ClassLoader.loadClass(ClassLoader.java:307) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301) at java.lang.ClassLoader.loadClass(ClassLoader.java:248) Exception in thread "main"

I have searched google for this and have found that couple of guys have faced this issue but none of them seems to be solving my issue. This can probably be due to difference in platforms

My development platform is as follows

OS: Windows XP
Eclipse JUNO
JUnit4
Maven2

Mean while, If I run this project using maven it runs absolutely fine.

The most strange part for me is the name of the class for which ClassNotFound Exception is thrown. Name of the class is of.

This is what blows me completely.

Also, what ever stack trace I have listed above, that is all what I get when I get the error nothing else.

I have been stuck in this issue for 2 days now, any help would be greatly appreciated.

Answer 1

I tried everything mentioned here and in other posts. Some of the solutions that people proffered were:

1. Change the output folder for the test
2. Create a custom builder for the project that would run test-compile from Maven
3. Move the Maven dependencies higher in the Order and Export list in the project build path

There were many, many more but the one that I found to work was as follows: Close the development environment. Delete the jars used by the project from my local Maven repository. Open the IDE. Build the project. Run the test.

After hours of beating my head against my keyboard and following suggested solutions, this one worked! If that doesn't work, you can try searching for the solutions I listed above.

Answer 2

Right clicking on the project name in Eclipse and choosing "Maven --> update project" will often solve this problem.

Answer 3

I know this question has already been answered but I will still share my solution here,

1. Make sure the output folder of 'src/test/java' has been set to 'target/test-classes', this has been said in many other posts so I will not repeat here.

2. If it still does not work, it is very likely that there are errors during the compiling of your unit test classes. Go 'Window' -> open 'Error Log' view, you should be able to see the detail of the error message.

For my case, a previously downloaded dependency jar is somehow corrupted due to network problems, so just delete the jar from local repository and use 'maven' -> 'update configuration' to download it again.

Then everything works!

Answer 4

Normally when we build we check "Skip Tests" in "Run configuration tab", instead uncheck "Skip Tests" and build the project the junits should work fine. This solution worked for me.

Answer 5

try switching the perspective to JUnit in eclipse and run the tests again

Answer 6

Despite all the answers and other posts I saw. I will give a summary of my effort:

it is probably this project's configuration doesn't fit with other projects in the same workspace. ( how to solve this is probably another question )

so, close this workspace, start a clean workspace for this project alone.

Answer 7

Was facing the same issue. This simple step solved it for me.

1. Remove JUnit from the project's Build Path and Add it again.

2. If set to Build Automatically, your workspace would be built again. If not set to Build Automatically then build your Project. Your issue should be solved.

Answer 8

You should add classes you use for example (spring-boot):

@RunWith(SpringRunner.class)
@SpringBootTest(classes = {DataPoint.class})
public class DataPointTest {

    @Test
    public void TestBuilder() {
        DataPoint.Builder builder = new DataPoint.Builder();

        DataPoint dataPoint = builder.withCount(4).withFirst(1).build();

        assert dataPoint.getCount() == 4 && dataPoint.getFirst() == 1;
    }

}

Answer 9

You can also check the info in POM.xml

I had the same issue. My project name was mismatching while setup the code.

<groupId>CucumberTest</groupId>
<artifactId>com.ProjectName</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>

<name>com.ProjectName</name>
<url>http://maven.apache.org</url>

After changing the project name in POM.xml it was working fine.