As the question suggests , I want to know the similarity between the sleep and join methods on the thread. I have gone through many questions that describe the difference betwee
It's not clear to me what your actual question is, but your third sentence in says, "I would like to know different scenarios where the sleep and join methods could be used interchangeably."
From a practical point of view, if you worked with a team of software developers writing production code, there would be no scenarios in which other developers would permit you to use join(long) as an alternative to sleep(long). No way, no how! It does not matter that there are circumstances under which it would actually work.
Production code should be readable. The intent of the code should be obvious to others. It should obey The Principle of Least Surprise (See Clean Code: A Handbook of Agile Software Craftsmanship by Robert C. Martin). That means, when you write foobar.join(n), you should be expecting the foobar thread to die. You might be prepared to handle the timeout case, but that should be the exception, not the rule. There is no other legitimate reason to call join(n). Anything else would be a "hack", and we do not put hacks in production code.