If you are bound to Java platform the best way to “be dynamic” IMHO is to work with Groovy.
Apart from the http://groovy.codehaus.org/ where you can find documentation, getting started examples etc. there are many blogs around that blog about groovy.
My favorite (although very slow) is Andres Almiray’s blog. He mostly blogs about griffon and groovy and has nice tutorials and examples. There I found info about many open source libraries I never heard of but which are quite useful, for example: FEST, Glazed list, Swing clarity, etc.
Try Groovy cause it’s groovy 🙂
I felt like when I run my first program at elementary school and it wrote “Ninja” on the screen 🙂