Errata

I already wrote to Allen Downey about this - but I want to make sure that this does not get lost in 100s of emails we get these days.

This is not really an error - the program behaves as designed but I am sure many readers of this book will not spend enough time to investigate and might put blame on the author or the publisher - may even put some nasty comments on Amazon.com pushing some potential buyers away which will be such a shame because

THIS IS AN AMAZINGLY WELL WRITTEN BOOK.

I am executing the class Class WikiPhilosophy.

When you start with https://en.wikipedia.org/wiki/Java_(programming_language) as the source URL,
the Third URL that is parsed for content (https://en.wikipedia.org/wiki/Computer_language) has only one PARAGRAPH element,
<p>A <b>computer language</b> is a system of communication with a computer. Types of computer languages include these:</p>

And it has no hyperlinks inside, the hyperlinks are kept outside of the paragraph as a list – the method WikiFetcher.fetchWikipedia (String url)
faithfully comes out saying it found no links (in <p>). In other Wikipedia pages the lists are kept under PARAGRAPHS.

So basically what Allen says on page 56 last paragraph point#4 ("after following 7 links you should get to Philosophy" does not happen because most probably the wikipedia page was changed.


I tested the program with a different input –

public static void main(String[] args) throws IOException {
String destination = "https://en.wikipedia.org/wiki/Philosophy";
String source = "https://en.wikipedia.org/wiki/Philosopher";
testConjecture(destination, source, 10);
}

And it works fine –

Fetching https://en.wikipedia.org/wiki/Philosopher...
**philosophy**
Eureka!

Thank you.

Regards,
Sumant