Need Resources to Learn Java Web Services from SCRATCH

I've bounced around Java and C# the last several years but now want to get up to speed with Web Services (RESTful). I used to be a master of J2EE circa 2003, but have since got side tracked into all kinds of stuff. I've worked through a couple of NetBeans tutorials (my IDE of choice) but they don't seem to expose the nitty gritty. I enjoy seeing how things exactly work, building an app from the byte array up.

Although I've touched a couple of fram开发者_高级运维eworks, I've most enjoyed working with Java EE proper to understand the base case before the sugar of Spring/Hibernate is added.

Does that make sense? I am looking for a book or tutorial that really builds up your knowledge piece by piece so that you understand everything, not some Rails-like toolkit for rapid development.

Thanks-in-advance,

Guido

I'd start by doing a review of HTTP, since in practice this is a fundamental building block of REST web services, and it gets you into the right mindset for what comes next.

Next, think about how you'd structure the URIs for various resources. Martin Fowler wrote a good article on this topic. Various java frameworks for creating web services try to make it easier for you to map requests to specific methods, and even to map parts of requests (including path elements, query parameters, and the entire request body) straight into your object model. But all of this just help with the identification and manipulation of resources through URIs.

Next, if your resources are related, then think about hypermedia controls. You're probably used to putting <a href=""> links in web pages, and you certainly wouldn't want people to hardcode or bookmark every single URL in your website. How does the same idea extend to web services?

Next, think about actually moving data between client and server. JSON or XML? URI element or query parameter? Again, lots of java frameworks exist just to make this easier -- for example, Jackson and Gson for REST, JAXB for XML, etc. -- but the problem of dealing with HTTP-based requests and responses is very similar to the one that your average servlet container solved years ago.

Finally, consider security. For example, username/password or OAuth? HTTP or HTTPS?

There are lots of other details, but these topics should keep you busy for a while.

Have you checked out Jersey yet? This is the Java reference implementation of JAX-RS. There is a great community around this project, and the main author is available via mailing lists and forums and has personally answered questions of mine for some gnarly situations I ran into. The jersey site has a lot of great links to get you started from a variety of angles, depending on what you're interested in learning.

RestifyDayTrader has very good details of how to build a RESTFul service. Java implementation can be found at Restified Trader

Java Web Services is a good read on learning Web Services.