Tuesday, July 29, 2008

Eclipse Tools You Should Be Using

I've written enough Java code in Emacs, Notepad, and Nano to know a good thing when I see it -- and Eclipse is a good thing! Pretty colors, line numbering, and CTRL+Space!! But seriously, there are a lot of cool things you can use with the software to make it even better.

Saving Tactics
It may seem a bit tedious, but I've got my Eclipse set up to do a bit of formatting every time I tap CTRL+S (which is a lot). It organizes my imports, formats my if statements, cleans up my whitespace, and, of course, saves the file. There are a number of options that differ version-to-version so I won't go into specifics but this is a nice way to keep your code clean and readable, especially working in a team environment.

Write buggy code? Fall into silly bug traps? Too lazy for JUnit? Or just like to try new plug-ins? Try out FindBugs! You can run it fairly quickly over your project and let it discover common ocde flaws, bad paterns, code smells, and code that's just on the fritz. Trust me.

Code Templates
Whether its method signature templates, comment defaults, or javadoc headers, using project-specific class templates are a great way to give your code formatting consistency. For example, I am working on an open-source project and need to include appropriate licensing headers atop each class. So instead of using copy-and-paste each time I make a class, all classes I create in my project automatically start with this text.

Of course, there's tons of things I haven't touched on here but these have greatly impacted my coding and make the process not only quicker and easier for me, but gives me better quality code as well. Maybe some of you can benefit as well! I also left some references you may find useful. Feel free to add others in the comments. 'Til next time!

Carl Scott
Software Developer, Solertium Corporation
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Friday, July 25, 2008

RESTful Client-Side tools for GWT

I guess this is more of an announcement than a blog, but I just wanted to do a quick follow up to my last blog to mention some new developments pertaining to using a RESTful approach to GWT.

In my last blog, I spoke of RestLet, a server-side Java framework for REST. When I first learned of this technology, my cronies at Solertium Corporation and I fully embraced the concept, even doing some development on the open-source tool. Between then and now, I have been experimenting with client-side tools that provide reliable API through GWT to a RESTful server.

I first found GWT-REST, which if you saw my comments, I found to be pretty usable. Like the original developers of RestLet, though, I found it to have almost too much going on to make it work for me at the time. In addition, since, at the time, I have a strong code pattern that worked, it didn't make me want to go through the trouble of refactoring. After speaking with their development team, though, it looks to be strong in the future.

Since then, the RestLet guys have announced the release of a Restlet-GWT module, a port of RestLet to GWT, supported by the release of GWT 1.5. You can check out the official announcement here:

I am interested in seeing the differences between this and GWT-REST, but from my initial reading it seems that the RestLet version is an attempt at a direct port as opposed to something customized to have client-side conveniences implemented -- which I feel has strong and weak points, but the good should outweigh the bad here. I'm excited to see the implementation details, though! If you want a quick overview, the RestLet wiki provides pretty pictures and diagrams:

Again, I want to express that the RESTful method is more of an alternative to RPC than a replacement, both having benefits and drawbacks. The main drawback to RPC that has turned me to this approach is the tight client-server coupling issues and the limitations it enforces on your back-end server technologies.

My suggestion -- give Restlet's GWT module a shot. Like I said, it's an alternative, and it works right alongside RPC so it's not an either-or situation. We all have our own ways of getting the job done, but I'm always excited to hear of new developments and try them out, especially ones like these which make my job that much easier!

Thanks for your time in reading this. Feel free to comment with opinions for or against REST in GWT as I'd love to hear both sides. Also, if you'd recommend any technologies, again, feel free.

Carl Scott
Software Developer, Solertium Corporation
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Monday, April 28, 2008

The Internet: An Alternative to GWT's RPC

This blog is aimed at software developers currently or considering using Google Web Toolkit (GWT), and assumes you have some prior knowledge/background. I do not aim to be technical in this blog, but rather, simply expose the idea and provide insight to those loathing particular programming paradigms.

Google's Google Web Toolkit (GWT) has make remarkable breakthroughs in allowing Java developers to easily create websites and web-based applications with little concern about cross-browser issues. As a software developer fitting this niche, I must say I am more than happy with what GWT provides.

That said, one of the biggest complaints about GWT is it's Remote Procedure Calls (RPC). In a nutshell, your client calls a function through an interface which the server interprets, executes, and returns a Java representation of results. The actual process is somewhat annoying to implement, can be somewhat clunky, and can have the speed of the DMV lines at the end of the month. Ok, so I'm exaggerating a bit, but it's nuiances were enough to me to choose to never go back to RPC. In addition, I don't think my server should be returning me a Java Object. If I wanted to access this outside the context of my GWT application (hey, these "crazy" things may happen), I know Internet Explorer probably can't render it too well -- it has a hard enough time with HTML (zing!).

Allow me to re-introduce the concept of REST.

Representational State Transfer (REST) is an architecture style that, well, kinda does what it says. In the context of Web Apps, it defines how we define, locate, and access resources. If you want the whole scoop, I've got reference links at the bottom. For this exercise, you just need to understand resources and representations.

A resource is the conceptual target of a reference (the reference being, generally, a URL). A file, for example, could be considered a resource. The file's representation can be a number of things, but examples are HTML, XML, GIF image, basically what the user sees. In short, it represents a resource in some meaningful way. For this exercise, let's go with XML as our default representation (it will become painfully apparent why soon).

With RPC, using a method to retrieve some data (a Representation, perhaps) is the standard means. There is a RESTful way to do this a well, and here's the kicker: it's a basic building block of the Internet! The standard CRUD (Create, Read, Update, Delete) operations are already represented as HTTP PUT, GET, POST, and DELETE, respectively. I'd argue that just about anything you'll need to do with a web application can be covered by one or a combination of these functions. I'm not going to get technical today but take my word for it.

Enter RestLet. A lightweight, open-source Java API that acts as a catalyst in developing Web Services in Java to handle ANY general HTTP request. A request from, say, our Web-based GWT application! RestLet employs the principles of REST, transferring representations from the server to the client upon request. Assuming we use XML Represenations, we already have a means of parsing and interpreting these representations client-side ... AJAX, which is at it's core, GWT.

Now, we have a generalized API to program to and access data from. We can use GWT to make requests, but now JSNI, JSP, PHP, even standard HTTP requests are respected. We have a portable server to interpret our requests and the responses (XML representations) are immediately parsable, even by IE (zing!).

In short, employing the principles of REST to ANY web app is incredibly beneficial for a number of reasons that I'll leave to the avid reader to convince themselves of. Roy Fielding has spent plently of time stating things and I don't need to use more. RestLet, an open-source project provides a well-thought out means of utilizing this architecture. And with this, you can finally give that RPC code a REST.

I wanted to use this blog to simply introduce the concept of REST within the context of GWT, how it can be leveraged by AJAX, and how it can be used as an alternative to RPC. If there's any interest, I'll do a follow-up blog or blogs that will delve into the following topics:

  • Current Open-Source Applications using REST/RestLet and GWT.
  • Open-Source Solutions made to speed up XML processing and leverage REST.
  • Creating a RESTful Web Server
  • RESTful References and Why They're Essential

This is all information you can dig up yourself, but I'm happy to share. REST and RestLet, of course, aren't the only way to get outside the RPC box, but, from my experience, it works efficiently, encourages robust code, and, most importantly for me, let me say bye-bye to RPC.

To close, I want to say that I don't profess to be a definitive authority on this, and I'm still learning new things everyday. I look forward to any feedback on this you may have, and any other out-the-box ideas.

Carl Scott
Software Developer, Solertium Corporation
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