Question

I am currently developing a program that can execute JUnit test cases on external classes. These external classes are sent in by students and we would like to evaluate them.

I have the following test case

import static org.junit.Assert.*;
import org.junit.Test;

public class Task1Test {

    @Test
    public void testAdd() {
        Task1 t = new Task1();
        int a = 5;
        int b = 11;
        assertEquals("Wrong add result", a+b, t.add(a,b));
    }
}

and I compiled it with:
$ javac -cp .:../lib/junit/junit-4.11.jar Task1Test.java

The Task1 will be a student’s class, but for now it is just a sample class with an add method that will return a wrong result. The file Task1.java is located in the same folder as Task1Test.java.

In my program I load the test case class and try to run it with JUnitCore:

String testsPath = "/path/to/classes";
String junitJar = "/path/to/junit-4.11.jar"
URL taskUrl = new File(testsPath).toURI().toURL();
URL[] urls = new URL[] {taskUrl,junitJar};

@SuppressWarnings("resource")
ClassLoader loader = new URLClassLoader(urls);
Class<?> clazz = loader.loadClass(task);

Result res = JUnitCore.runClasses(clazz);

if(!res.wasSuccessful()) {
    for(Failure f : res.getFailures()) {
        System.out.println(f.toString());
    }
}

However, it does not work as expected. When I run this code, I get this message:
initializationError(Task1Test): No runnable methods

When I look into the loaded class using reflections, I can see that the method testAdd has no annotation (i.e. method.getAnnotation(org.junit.Test.class) returns null).

Does anyone have an idea? Did I forget a compiler switch or anything?

I am using Java 1.7.0_11 and the code is run in an web application on Glassfish 3.1.2.2

EDIT:

I can run the test case from command line with:
$ java -cp .:../../code/lib/junit/junit-4.11.jar:../../code/lib/junit/hamcrest-core-1.3.jar org.junit.runner.JUnitCore Task1Test

Answer 1

I found a solution from this answer
I did not set a parent class loader, which seems to have caused the trouble. Setting it as it was said in the other answer it now executes the test.