Entry 16 - I Want to be an Expert in Java Web Development

I've been doing Java web development for more than 5.5 years already and I thought I knew a lot.  The truth though is totally different.  What I knew from my development work was how to code using the framework that was provided.  What's  behind the framework, that's where I have a lot to learn about.  I realized this during my time trying to look for work.  Some of the exams I took and the interviews I had showed me that I still had a lot of things to learn about.  One of my goals is to be an expert on this, someone who knows the ins and outs of Java web development.  How do I achieve this?  For a start, I have started reading some Java books and not just reading, but really understanding the Java technology.