Raible Designs

My Future of Web Frameworks Presentation

Earlier this week, I tweeted about a history of web frameworks timeline I created for my upcoming Future of Web Frameworks talk at TSSJS Vegas 2010. I immediately received a lot of feedback and requests for adding new frameworks and releases. The image below is the result of that Twitter conversation. Thanks to everyone who contributed.

Back in November, I wrote about my proposals for TSSJS. I've been thinking a lot about web frameworks lately and I can't help but think we live in a very exciting time. As a Java developer, I've been exposed to one of the most vibrant language ecosystems on the planet. As Tim Bray talks about, the Java Platform has 3 legs: the language, the virtual machine and a huge, immense library of APIs (both in the JDK and in open source libraries). The diagram below is something I created based on Tim's podcast.

Tim says, "One of those legs is replaceable and that's the language." And he's right, there's many Java.next languages that run efficiently on the JVM. This is one of the most exciting parts of being a Java web developer today. There's many proven web frameworks and languages that you can pick to build your next web application.

The best part is many of the best web frameworks run on the JVM. Not only that, but the best code editors are the IDEs that you're familiar with and have grown to love. Furthermore, much of the literature for Java.next languages is written for Java developers. As someone who knows Java, you have wealth of web frameworks and languages just waiting for you to learn them.

To create my presentation on the future of web frameworks, I followed the outline I posted previously. I plan on explaining the evolution and history of web frameworks and how we got to where we are today. From there, I'll be speculating on what web applications we'll be developing in the future. Finally, I'll touch on the necessary features of web frameworks that will allow us to develop these applications.

Of course, I haven't actually presented this talk yet, so it's likely to change in the coming weeks before the conference. The good news is this gives you the opportunity to provide constructive criticism on this presentation and help make it better. I realize that a presentation rarely represents the conversation that takes place during a conference. However, I believe it can portray the jist of my thinking and lead to a meaningful conversation in the comments of this post. Below is the presentation I created - thanks in advance for any feedback.

For those who will be joining me at TSSJS ... it's gonna be a great show. St. Patrick's Day in Vegas, what more could you ask for?

Update: This article has been re-posted on Javalobby and contains additional community feedback in the comments.

What would you like to see at TSSJS 2010?

A couple months ago, I was asked by TheServerSide to speak at next year's TheServerSide Java Symposium in Las Vegas. In addition, they asked me to help them evaluate presentation proposals and suggest topics/speakers.

First of all, I think the biggest thing that TSSJS could do to improve is to host more networking events. With the JavaOne Party being over, I think there's a tremendous opportunity to fill a gap in the networking needs of the Java Community. When I first attended TSSJS in 2006, there were a fair amount of parties and everyone got to interact quite a bit. In 2008, there were no networking events. I believe having a strong networking story would attract a lot more attendees, companies and sponsors.

Secondly, I think it's possible that TSSJS has too many server-side related sessions. IMO, the server-side (and middleware in general) isn't that exciting. TechTarget appears to own TheClientSide, so why not add some more client-side stuff to the mix? For example, I'd love to see a Struts 1 app-makeover using different technologies (for example, Flex, GWT and jQuery). I think HTML5 and Google Wave's Architecture sessions would be interesting too. If adding client-side sessions is too far away from TheServerSide, maybe it should be renamed to TheServerSide JVM Symposium and there can be all kinds of sessions on JVM languages (e.g. Scala, JRuby, Groovy) and all the great things those languages can accomplish.

Lastly, I've been asked to send a couple session proposals. Currently, I'm thinking about a doing GWT vs. Flex Smackdown with James Ward, but I'm open to other ideas. It's been quite awhile since I did a "Comparing Web Frameworks" talk. Maybe "Hot Web Frameworks for 2010" is more appropriate? I also think it'd be interesting to do a somewhat philosophical talk on "The State of Web Frameworks" and where we're headed in the next year.

What would make you want to attend TSSJS next year? Let me know your thoughts and I'll do my best to make them a reality.

Update October 22, 2009: Whoo hoo! It looks like TheClientSide will be a part of TSSJS Vegas next year. Should be a great show.

Concurrency on the JVM Using Scala with Venkat Subramaniam

This evening, I attending the Denver JUG where Venkat Subramaniam was speaking about Scala. Unfortunately, I arrived halfway through his Programming Scala talk and didn't get a chance to learn as much as I wanted to. What I did see made Scala look very powerful and (possibly) easier to learn than Java. Below are my notes from Venkat's talk.

Concurrency is important these days because we're in a world of multiple processors. When you have multiple threads running at one time, it can become painful. Before Java, you had to learn the API for multi-threading for each different platform. With Java's "Write once, debug everywhere", you only had to learn one API. Unfortunately, it's pretty low level: how to start a thread, manage it, stop it, etc. You also have to remember where to put synchronize in your code.

With Scala, immutability and its Actors make it easy to program concurrent systems. For example, here's a web service that retrieves stock prices in sequential order:

def getyearEndClosing(symbol : String, year : Int) = {
  val url = "http://ichart.finance.yahoo.com/table.csv?s=" + 
    symbol + "&a=11&b=01&c" + year + "&d=11&e=31&f=" + year + "&g=m"
  val data = io.Source.fromURL(url).mkString
  val price = data.split("\n")(1).split(",")(4).toDouble
  Thread.sleep(1000); // slow down internet
  (symbol, price)
}

val symbols = List("APPL", "GOOG", "IBM", "JAVA", "MSFT")

val start = System.nanoTime

val top = (("", 0.0) /: symbols) { (topStock, symbol) => 
  val (sym, price) = getYearEndClosing(symbol, 2008)

  if (topStock._2 < price) (sym, price) else topStock
}

val end = System.nanoTime

println("Top stock is " + top._1 + " with price " + top._2)
println("Time taken " + (end - start)/10000000000.0)

To make this concurrent, we create Actors. Actors are nothing but Threads with a built-in message queue. Actors allow spawning separate threads to retrieve each stock price. Instead of doing:

symbols.foreach { symbol => 
  getYearEndClosing(symbol, 2008)
}

You can add actors:

val caller = self

symbols.foreach { symbol => 
  actor { caller ! getYearEndClosing(symbol, 2008) }
}

Then remove val (sym, price) = getYearEndClosing(symbol, 2008) and replace it with:

  receive {
    case(sym: String, price: Double) =>
      if (topStock._2 < price) (sym, price) else topStock
  }

After making this change, the time to execute the code dropped from ~7 seconds to ~2 seconds. Also, since nothing is mutable in this code, you don't have to worry about concurrency issues.

With Scala, you don't suffer the multiple-inheritance issues you do in Java. Instead you can use Traits to do mixins. For example:

import scala.actors._
import Actor._

class MyActor extends Actor {
  def act() {
    for(i <- 1 to 3) {
    receive {
      case msg => println("Got " + msg)
    }
  }
}

When extending Actor, you have to call MyActor.start to start the Actor. Writing actors this way is not recommended (not sure why, guessing because you have to manually start them).

Venkat is now showing an example that counts prime numbers and he's showing us how it pegs the CPU when counting how many exist between 1 and 1 million (78,499). After adding actor and receive logic, he shows how his Activity Monitor shows 185% CPU usage, indicating that both cores are being used.

What happens when one of the threads crashes and burns? The receive will wait forever. Because of this, using receive is a bad idea. It's much better to use receiveWithin(millis) to set a timeout. Then you can catch the timeout in the receiveWithin block using:

case TIMEOUT => println("Uh oh, timed out")

A more efficient way to use actors is using react instead of receive. With react, threads leave after putting the message on the queue and new threads are started to execute the block when the message is "reacted" to. One thing to remember with react is any code after the react block will never be executed. Just like receiveWithin(millis), you can use reactWithin(millis) to set a timeout.

The major thing I noticed between receive and react is Venkat often had to change the method logic to use react. To solve this, you can use loop (or better yet, loopWhile(condition)) to allow accessing the data outside the react block. In conclusion, reactWithin(millis) is best to use, unless you need to execute code after the react block.

Conclusion
This was a great talk by Venkat. He used TextMate the entire time to author and execute all his Scala examples. Better yet, he never used any sort of presentation. All he had was a "todo" list with topics (that he checked off as he progressed) and a sample.scala file.

Personally, I don't plan on using Scala in the near future, but that's mostly because I'm doing UI development and GWT and JavaScript are my favorite languages for that. On the server-side, I can see how it reduces the amount of Java you need to write (the compiler works for you instead of you working for the compiler). However, my impression is its sweet spot is when you need to easily author an efficient concurrent system.

If you're looking to learn Scala, I've heard Scala by Example (PDF) is a great getting-started resource. From there, I believe Programming in Scala and Venkat's Programming Scala are great books.

Ajax Framework Analysis Results

Way back in January, I wrote about how my colleagues and I were evaluating Ajax frameworks to build a SOFEA-style architecture. To make our choice, we used the following process:

1. Choose a short list of frameworks to prototype with.
2. Create an application prototype with each framework.
3. Document findings and create a matrix with important criteria.
4. Create presentation to summarize document.
5. Deliver document, presentation and recommendation.

When I wrote that entry, we had just finished step 2 and were starting step 3. I first wrote this blog post a week later, when we delivered step 5. Here is the comparison and conclusion sections of the analysis document we composed.

Framework Comparison
In order to evaluate the different frameworks against important criteria, we created a matrix with weights and ranks for each framework. This matrix shows how our weighting and rankings lead us to the winner for our project. You can view this matrix online or see below for a summary.

Note: Criteria whose values were identical across all candidates were weighted at zero. Charting capability was weighted at zero b/c we decided to use Flash for this.

This matrix indicates that GWT is the best candidate for our team to develop SOFEA-style applications with. In addition to the matrix, below are graphs that illustrate interesting (and possibly meaningless) statistics about each project.

Conclusion
After working with the various frameworks, we believe that all the frameworks were very good and could be used to write applications with. If all weights are equal, these frameworks were almost even when compared against our evaluation criteria. The graph below illustrates this.

Even after applying the weighted criteria, the evenness doesn't change a whole lot.

Without considering the even or weighted criteria, we believe the decision all comes down to what the developers on the project feel they will be most comfortable with. If you're developing with Dojo or YUI, chances are you're dressing up existing HTML and possibly using progressive enhancement to add more rich functionality. On the other hand, Ext JS and GWT are similar to Swing programming where you build the UI with code (JavaScript for Ext JS, Java for GWT).

The tools available for JavaScript development have gotten increasingly better in recent years. IntelliJ IDEA has a JavaScript Editor that provides many of the same features as its Java editor. Aptana Studio also has excellent support for authoring and debugging JavaScript. However, we believe the Java debugging and authoring support in IDEs is much better. Furthermore, we are more familiar with organizing code in Java projects and feel more comfortable in this development environment.

Based on this evaluation, we believe that GWT is the best framework for our team to develop SOFEA-style applications with.

Flash Forward to Today...
The core GWT library from Google doesn't have a whole lot of widgets, nor do they look good out-of-the-box. So early on, we experimented with two alternative implementations that continue to leverage GWT concepts and tools:

• GXT: a GWT version of Ext JS
• SmartGWT: a GWT version of SmartClient

Unfortunately, over the past few months, we've found that both of these implementations are too heavy for our requirements, mostly because of the file size of the generated JavaScript code. For example, a feature I wrote generated a 275K *.cache.html file using GXT. After determining that was too slow to give users the initial "pop", I re-wrote it without GXT. After a day, we had an application with *.cache.html files of 133K. Yes, that's over a 50% reduction in size!*

Because of these findings, we are proceeding with the core GWT library from Google and adding in new components as needed. It is cool to know you can make a UI "pop" with GWT, as long as you stick to the core - close-to-the-metal - components. For those applications that can afford an initial "loading..." state, I'd definitely recommend looking at GXT and SmartGWT.

* To make refactoring easier, I copied GXT MVC into our source tree and modified all imports.

GWTTestSuite makes builds faster, but requires JUnit 4.1

Earlier this week, I spent some time implementing GWTTestSuite to speed up my project's build process. In Hudson, the project was taking around 15 minutes to build, locally it was only taking 5 minutes for mvn test. In IDEA, I could run all the tests in under a minute. While 15 minutes isn't a long time for a build to execute, a co-worker expressed some concern:

Does Maven have to run GWT test and individual Java processes? (See target/gwtTest/*.sh) This arrangement and the overhead of JVM launches is another reason why builds take so long. As we add more GWT tests we are going to test that LinkedIn record for the slowest build ever.

After this comment, I started looking into GWTTestSuite using Olivier Modica's blog entry as a guide. It was very easy to get things working in IDEA. However, when I'd run mvn test, I'd get the following error:

Error: java.lang.ClassCastException

No line numbers. No class information. Zilch. After comparing my project's pom.xml with the one from the default gwt-maven archetype, I noticed the default used JUnit 4.1, while I had the latest-and-supposedly-greatest JUnit 4.4. Reverting to JUnit 4.1 fixed the problem. Now Hudson takes 3:15 to execute the build instead of 15 minutes.

The reason for this blog post is this doesn't seem to be documented anywhere. Hopefully other developers will find this entry when googling for this issue.

Related to making GWT faster, I also added the following line to my Application.gwt.xml file:

<set-property name="user.agent" value="safari" />

This dropped the gwt:compile time from 1 minute to 25 seconds. As explained in the documentation, you can use the "user.agent" setting to only generate one JS file for your app instead of 4. The strange thing about adding this setting was I pretty much forgot about it since everything seemed to work fine on both Safari and Firefox. When I started testing things in IE6, I started seeing a lot of JavaScript errors. After debugging for an hour or so, I realized this setting was there, removed it, and everything started working great in all browsers.

Now if I could just figure out how to use safari-only for development, but remove the line when building the WAR. Suggestions welcome.

What's the best Java Hosting Solution?

A friend recently asked me who I'd recommend for a Java hosting provider. Since I get asked this question every-so-often, it seemed appropriate to post my answer here.

1. KGB Internet - I use KGB for this site. I have my own JVM and have full control over what I want to install. I can control Tomcat versions and upgrade as needed. I don't know if I'd recommend him for a business site as he can take up to 12 hours to respond to requests.
2. Kattare - These guys will give you your own Tomcat instance and seem to have reasonable prices. They do seem to take quite some time to respond to requests (24-48 hours). I have a free instance that I use for a non-profit, so that could be the reason.
3. Contegix - These guys are far-and-away the best company for Java-based hosting. They're not cheap though. However, they have the best customer service in the business - often responding to e-mails in less than a minute.

Do you agree with these recommendations? If not, who do you recommend for Java hosting and why?

Grails vs. Rails - My Thoughts

In a comment, Jared Peterson asked:

I'm curious if you have any thoughts on folks that might be trying to make a decision between Rails and Grails. I like the concept of "Allow Both", but what if you "have neither"?

If you were starting a new project, could choose either one, needed to interact with a lot of existing Java code (JRuby on Rails I guess), what would you pick?

A friend recently asked me "Can I solicit your honest, unadulterated opinion on Grails?" I think the e-mail I sent him may help Jared's question.

I think it's awesome. IMO, it's the same thing as AppFuse, but it has a DSL that's much simpler to learn and remember. Less code -> faster productivity. There does seem to be some maturity issues, but I think it'll get there. The question is - how fast can Groovy become. It's similar to Rails and Ruby in that you start using Grails and you think "This Groovy thing is kinda cool, I'd like to learn more." One of the reasons I really like it is the learning curve for experienced open source Java Developers is virtually flat. You can learn enough to be productive in a single day.

That being said, I think there's also a lot of cool stuff going on with RIA. IMO, Flex or GWT + Grails would be a really fun set of tools to develop with. Here's a excerpt from a write-up I recently did when analyzing Rails and Grails at LinkedIn (in January):

--------
Comparing Rails and Grails
They're both excellent frameworks. Rails is definitely more mature, but the environment is a pain to setup (esp. on Windows). Grails is very easy to setup for Java Developers. Grails needs a lot of improvement as far as hot deploy and stack traces. It's probably Groovy's fault, but its stack traces are hideous - rarely pointing to the class and line number in the first few lines.

As for hot deploy, it doesn't work nearly as well as it does with Rails. Rails' "script/server" starts WEBrick in a few seconds, while "grails run-app" can take up to 10 seconds (even on a brand new application). Even with its warts, Grails is simply awesome. I really, really enjoy writing Groovy code in IDEA and seeing immediate changes. I don't like "test-app" as much as I like Rails' "test:units" (or even better, "test:uncommitted"). It seems to be widely realized that Rails has a better testing story.

Rails is immediate, Grails is immediate 70% of the time.

Groovy is extremely easy to learn for Java Developers. Ruby is easy too learn, and possibly too powerful for OO rookies. Both are fun to program in and very capable of allowing greater developer productivity. If you know Hibernate, Spring, SiteMesh and JSP, you owe it to yourself to look at Grails. If you know these technologies well, you can learn Grails in less than an hour. You can be productive in the next hour and have an application running by the end of the day. That's not to take anything away from Ruby. I believe that Rails is an excellent platform as well. It's pretty cool that profiling and benchmarking are built into the framework and you can easily judge how many servers you'll need to scale.

I used IDEA while developing with both frameworks. IDEA has Rails and Groovy support available via plugins and they both worked quite well. The support for Grails was much better than Rails. Grails offers code completion, Ctrl+click on classes/methods, debugging and starting/ stopping the webapp from your IDE. Rails doesn't offer much in the way of Ctrl+clicking on class names/methods or debugging.
--------

Is there anything that Rails can do that Grails can't? Not as far as I can tell. I think it really comes down to developer passion and team preference. If you have experienced Java Developers that like the ecosystem and its tools, Grails makes a lot of sense. If you have experienced PHP developers or frustrated J2EE developers, they might enjoy Rails more. One thing that's very cool about both frameworks - learning one actually teaches you things about the other. They're so similar in many respects that knowledge is transferable between the two.

Of course, this is all just my opinion after working with both frameworks for a few weeks. For anyone who has tried both, what do you think?

In closing, here's an excerpt from a recent comment I left on Javalobby:

Of course, the hard part now is deciding between Django, Rails, Grails and GWT for your web framework. Then again, that's like having to choose between a Ferrari, Porsche, Lamborghini and a Maserati. No matter which one you choose, it's unlikely you'll be disappointed.

David Sachdev on Web Framework Proliferation

David Sachdev left the following comment in my post about the Java Web Framework Smackdown at TSSJS in Vegas:

Wow - that's quite a mouthful David. Well written!

P.S. The Early Bird Deadline for TSSJS is today.

There is no "best" web framework

From Mike Clark's blog, I learned about a number of TED Talks. As a fan of Malcom Gladwell, I was drawn to What we can learn from spaghetti sauce. In this talk, he talks about the research that Howard Moskowitz did for spaghetti sauce and how it changed the food industry forever. Here's a couple of quotes I wrote down:

"When we pursue universal principles in food, we aren't just making an error, we are actually doing ourselves a massive disservice."
...
"The difference between coffee at 60 (% satisfied) and coffee at 78 is the difference between coffee that makes you wince and coffee that makes you deliriously happy."
...
In embracing the diversity of human beings, we will find a sure way to true happiness.

Can this thinking be applied to web frameworks as well? What if it's not about choosing the best framework for your type of application? What if it's all personality related?

» Read more and comment on Javalobby.

Grails 1.0 and JRuby on Rails on WebSphere

A couple of interesting things happened today that relate to my Grails vs. Rails quest for knowledge.

The first is that Grails 1.0 was released. This was apparently a huge event as it swamped Codehaus' servers for a couple hours. This morning, it was pretty cool to shake Graeme's hand and congratulate him on the release. I also got to meet Jeff Brown for the first time. Who needs to go to a conference when you get to talk to these guys at work?

Secondly, I found an article by Ryan Shillington that shows how to deploy a Rails application to WebSphere. To me Rails + WebSphere seems like the last thing a Rails advocate would want - but who knows. In my experience, most developers that use WebSphere don't do it by choice.

For companies that have invested a lot of time and money into the JVM as a platform, it seems like Grails is the clear winner over Rails. However, the line gets blurry when you start talking about JRuby. I think JRuby will get there, but I don't believe it's there yet. If you look at the two major JRuby on Rails success stories (from Oracle and Sun), they've had to fix performance issues as part of their projects. With big companies investing in the platform, it's highly likely performance will be fixed in the near future. I believe both the Groovy and JRuby teams have said performance enhancements are their top priority for their next releases.

I think the biggest news related to performance of dynamic languages on the JVM is the new Da Vinci Machine project.

This project will prototype a number of extensions to the JVM, so that it can run non-Java languages efficiently, with a performance level comparable to that of Java itself.

Dynamic languages on the JVM seem to have a very bright future.

I got involved with Struts and Spring just before their 1.0 releases. Is it simply a coincidence that I happened to start looking into Grails right before its 1.0 release?