How to assert greater than using JUnit Assert?

Just how you’ve done it. assertTrue(boolean) also has an overload assertTrue(String, boolean) where the String is the message in case of failure; you can use that if you want to print that such-and-such wasn’t greater than so-and-so.

You could also add hamcrest-all as a dependency to use matchers. See https://code.google.com/p/hamcrest/wiki/Tutorial:

import static org.hamcrest.MatcherAssert.assertThat;
import static org.hamcrest.Matchers.*;

assertThat("timestamp",
           Long.parseLong(previousTokenValues[1]),
           greaterThan(Long.parseLong(currentTokenValues[1])));

That gives an error like:

java.lang.AssertionError: timestamp
Expected: a value greater than <456L>
     but: <123L> was less than <456L>