needs mockito library

StreamMock.java

public class StreamMock {

	/**
	 * Will create a mock object. When one of the methods of this mock object is
	 * invoked, it will write information about this method-call to the given
	 * printstream.
	 * 
	 * @param clazz
	 * @param out
	 * @return
	 */
	public static <T> T streammock(final Class<T> clazz, final PrintStream out) {
		final T t = Mockito.mock(clazz, new Answer<T>() {

			@Override
			public T answer(InvocationOnMock invocation) throws Throwable {
				final String methodname = invocation.getMethod().getName();
				final String str = new StringBuilder()
						.append("mock: ")
						.append(invocation.getMethod().getDeclaringClass()
								.getCanonicalName()).append(".")
						.append(methodname)
						.append(Arrays.asList(invocation.getArguments()))
						.append(";").toString();
				out.println(str);
				return null;
			}
		});
		return t;

	}

}