...

I don't think it is quite correct to call this a course; it's more of a
lecture on Java programming concepts and techniques. In my opinion, a course
has exercises that the student is supposed to do and solutions should be
provided so that the student knows if they have the correct solution. The
material at the link does not appear to have any exercises at all.

The chapter on Object-oriented programming seems very weak to me.
Inheritance is mentioned very briefly and many of the other key OO concepts
like encapsulation and overloading don't see to get mentioned at all.
Failing to teach a prospective Java programmer about OO concepts almost
guarantees that the person will not write proper OO code. That makes this
material a very poor choice, in my opinion.

Also, the material is awkward to navigate. There are no "next" or "previous"
page links so I always have to click the back button in my browser to go
back to the index, then, select the next page I want to read. If the index
and the rest of the material were all on the same page, that wouldn't be a
problem but the designer of the site apparently chose not to do that.

Just my two cents worth....

Rhino