Create mock object using jMock.

gistfile1.groovy

import org.jmock.cglib.MockObjectTestCase;

public class ExampleTest extends MockObjectTestCase {

    public void testExample() throws Exception {
        ...
        final Mock mock = new Mock(ClassName.class);
        mock.expects(once()).method("methodName").will(returnValue("returnValue"));
        mock.proxy();
        ...
    }
}