JUnit.org Resources for Test Driven Development

The Javadocs at JUnit.org do not give you a lot of information on how the methods behave. For example, when calling assertEquals and passing in two objects, does the method "under the covers" call the equals method (if any) for those objects to compare them? I don't think it simply compares object references ... but I could be wrong.

So is it OK to do this:

assertEquals("14:23:33", formatTimeVar);

or should one do this to be "safe":

boolean result = formatTimeVar.equals("14:23:33");
assertTrue(result);