Hi, I am looking for some good tutorials or books on how to build a web framework from scratch, the platform of interest is the JVM and I would like to know more about basic concepts such as routing, filtering and how the request/response cycle is handled.
Most frameworks rise out of a specific set of practices and an effort to automate those practices. Which means that they are usually built bottom up rather than top down. Rails is a primary example where 37 Signals built a framework that automated away the all the plumbing it was doing job after job building applications.<p>The tendency toward bottom up development is probably a reason there are so many frameworks...everyone has different practices that need automating.
The best way would be to learn from one of the existing open source projects.<p>You can start with sparkjava: <a href="https://github.com/perwendel/spark/" rel="nofollow">https://github.com/perwendel/spark/</a><p>Also, multi-threading, I/O and networking are areas that you would need to understand inside out.