JUnit showing erro java.lang.NoClassDefFoundError: org/junit/runner/manipulation/Filter

Question

# Junit not working giving error #

Tried testing basic add operation using Junit its showing this error on my mac

# AddTest.java #

    import static org.junit.Assert.*;

    import org.junit.Test;

        public class AddTest {

    @Test
    public void Addtest() {

        MyJUnitClass junit = new MyJUnitClass();

        int result = junit.add(100, 200);
        assertEquals(300, result);
       } 

        }

# MyJunitClass #
    public class MyJUnitClass {
    public int add(int a, int b) {
        return a+b;
    }

    public String conCat(String a, String b) {
        return a+b;
    }
        }



java.lang.NoClassDefFoundError: org/junit/runner/manipulation/Filter
    at java.base/java.lang.Class.forName0(Native Method)
    at java.base/java.lang.Class.forName(Class.java:332)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.loadTestLoaderClass(RemoteTestRunner.java:380)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.createRawTestLoader(RemoteTestRunner.java:370)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.createLoader(RemoteTestRunner.java:365)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.defaultInit(RemoteTestRunner.java:309)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.init(RemoteTestRunner.java:224)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:208)
Caused by: java.lang.ClassNotFoundException: org.junit.runner.manipulation.Filter
    at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:583)
    at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)
    at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521)
    ... 8 more

This is the error I am getting while running I have placed the JUnit 4.jar file libraries in buildpath. My I am able to access all the functions from JUnit jar file but when I run the JUnit test I get Failure error and this message in console.

Answer 1

You should try "add library", and then choosing JUnit, not adding a jar directly ! Good luck :)