Exercises on using Java API
<p>Is there a tutorial / book / website that teaches you how to use the Java API? So, let say I am already in this website: <a href="http://download.oracle.com/docs/cd/E17476_01/javase/1.4.2/docs/api/" rel="nofollow">http://download.oracle.com/docs/cd/E17476_01/javase/1.4.2/docs/api/</a></p>

<p>What are these packages / classes for? Or if I want to manipulate Strings... how do I know to use java.lang.String?</p>

<p>Then if I am in java.lang.String, I see there is the Interface, class and exception summary. I am sure somewhere there is a documentation that explains all of this. Also, I see a field, constructor, method summary... what are these?</p>
