Raible Designs

GWT Presentation with Bob Vawter

Tonight I'm in Mountain View attending the inaugural meeting for the new Silicon Valley Google Technology User Group (SV-GTUG). The good news about this meeting is Bob plans to discuss some of the new features in the GWT 1.5 release. Although it is not available yet, it sounds like they are putting the finishing touches on the 1.5 release and that it will be available soon.

The first ting I've learned is that GWT is actually pronounced "gwit". Bob is a member of the GWT team and he's the only one that's not based out of Atlanta. GWT has a very Swing-like programming model. It has widgets, panels and windows and operates very much like a traditional UI programming API. To create an application, you create a class that implements EntryPoint. Below is an example Hello World application.

One of the really nice things about GWT is that you can easily debug your application in your favorite Java IDE. GWT doesn't prevent you from writing JavaScript - you can insert native JavaScript into your code using a special /*-{ script here }-*/.

When you compile a GWT application, you get a whole bunch of stuff. When trying to develop cross-browser JavaScript code, you often end up with "if soup" to handle the different browsers. GWT does the same thing, but it creates different versions of the application for the different browsers. The naming of these files is an MD5 hash that's bootstrapped by a simple JS file. GWT files are all static and the file sizes are ~40KB/each for the Hello World application.

If you have to write fewer than 100 lines of code, it's likely that GWT will be overkill - you can do it with JavaScript easier. Once you get more lines of code and larger teams, Java's tools do all the heavy lifting. Yes, you can create large applications with large teams with scripting languages, but Java is the clear winner when you have large teams of developers working on projects.

GWT provides a RemoteService for client code and a RemoteServiceServlet for server-side code that you can use to implement RPC calls. For more information, see the Remote Procedure Calls documentation.

At this point, we're 45 minutes into the presentation and it's pretty disappointing. This is likely because there's no presentation and Bob doesn't seem to have any sort of agenda. I think this type of presentation would work well if folks had experience with GWT and were asking lots of questions. However, it seems that most folks haven't used GWT - so the questions (and his resulting answers) aren't very meaty.

One attendee asked about making GWT applications SEO-able. Bob's suggested solution is to continue to use Servlet or JSPs to render the page, but then use GWT to for the user interaction that needs to happen within the page. The RootPanel class has a get(String id) method that can be used to put the GWT application into a particular div or other placeholder.

Google Base and Google Checkout are currently using GWT. There's also a lot of Google internal development that uses GWT. Apparently, there's quite a few applications built with GWT that haven't launched yet.

Has anyone used the Maven Gwt Plugin? It sounds like it might be pretty nice as it contains the GWT compiler with no OS-dependent Google tooling.

The main new feature in GWT 1.5 is Java 5 support. There's also a GWT Incubator that's used to host GWT features that may go into GWT's core. You can view the demos online.

GWT's mission statement:

GWT's mission is to radically improve the web experience for users by enabling developers to use existing Java tools to build no-compromise AJAX for any modern browser.

GWT's competition according to Bob - Visual Studio.

Acegi Security 1.0.6 and Spring Security 2.0-M1

From the Acegi mailing list:

Release 1.0.6 is now available from Sourceforge:

http://sourceforge.net/project/showfiles.php?group_id=104215

This is a minor bugfix and maintenance release - the changelog can be viewed here:

http://jira.springframework.org/secure/ReleaseNote.jspa?version=10671&styleName=Text&projectId=10040

The jar files should also be available from the central maven repository.

Spring Security 2.0-M1
----------------------
This is the first milestone release of Spring Security 2.0. You can download it from:

http://static.springframework.org/downloads/nightly/milestone-download.php?project=SEC

The changelog can be found here:

http://jira.springframework.org/secure/ReleaseNote.jspa?projectId=10040&styleName=Html&version=10451

For maven users, the jars are available from the Spring milestone repository. For details on how to add this to your project, read Ben Hale's article.

I tried this release with AppFuse and all tests pass.

AppFuse 2.0.1 Released

The AppFuse Team is pleased to announce the release of AppFuse 2.0.1. This release squashes a number of bugs and includes an upgrade to Spring 2.5. To learn more about Spring 2.5's features, see InfoQ's What's New in Spring 2.5: Part 1 article.

For information on upgrading from 2.0, see the 2.0.1 Release Notes or changelog. AppFuse 2.0.1 is available as a Maven archetype. For information on creating a new project using AppFuse, please see the QuickStart Guide or the demos and videos.

What is AppFuse? Click here to find out.

AppFuse is an open source project and application that uses open source tools built on the Java platform to help you develop Web applications quickly and efficiently. It was originally developed to eliminate the ramp-up time found when building new web applications for customers. At its core, AppFuse is a project skeleton, similar to the one that's created by your IDE when you click through a wizard to create a new web project.

AppFuse 1.x uses Ant to create your project, as well as build/test/deploy it. AppFuse 2.0 uses Maven 2 to create your project as well as build/test/deploy it. IDE support is much better in 2.0 because you can generate the IDE project files with Maven plugins. AppFuse 1.x uses XDoclet and JDK 1.4+.

This project was started in April 2003.

The 2.0 series of AppFuse has a minimum requirement of the following specification versions:

• Java Servlet 2.4 and JSP 2.0 (2.1 for JSF)
• Java 5+

If you've used AppFuse 1.x, but not 2.x, you'll want to read the FAQ. Join the user mailing list if you have any questions.

Thanks to everyone for their help contributing code, writing documentation, posting to the mailing lists, and logging issues.

We greatly appreciate the help from our sponsors, particularly Atlassian, Contegix, JetBrains, and Java.net. Atlassian and Contegix are especially awesome: Atlassian has donated licenses to all its products and Contegix has donated an entire server to the AppFuse project. Thanks guys - you rock!

Please post any issues you have with this release to the mailing list.

Go Light with Apache Struts 2 and REST by Don Brown

After attending Dan's talk on REST, I stayed in the same room and listened to Don Brown talk about Struts 2's support for building RESTful applications. Below are my notes from the event.

What is wrong with today's web applications? You're using a modern web framework and you've cleanly separated your presentation and business logic. The biggest problem in modern web applications is Confusing URLs.

A URL should be a resource indicator - not a method invocation. Often, web applications have little or no caching. People use GET to perform data manipulation and POST may or may not change state (especially with JSF). Another big issue with modern web frameworks is there's too many abstraction layers that hide HTTP headers and it's difficult to manipulate them.

Today's applications are "information silos". There's a lot of information in your applications, but it's all buried in HTML, JavaScript and CSS. There's no way to get this information out of your application unless you explicitly expose it.

The answer to many of these problem is REST. It's the Way of the Web. To solve the information silo problem, you can create a single interface that has multiple representation of the same resource. There's one URI for all types of resources - be it XML, JSON or HTML. How does this work w/o modifying the URL? You modify the URL's extension.

Struts 2 has a couple of plugins that make developing RESTful services easier. The first is the Codebehind plugin and the 2nd is the REST plugin. Don is doing a demo with the REST plugin and shows that there's no Struts configuration files needed (no struts.xml and no struts.properties). The only thing that's necessary is to specify an "actionPackages" init-param on the DispatcherFilter in web.xml. This activates the Codebehind plugin that uses conventions to determine the view template's path.

In Don's demo, he's creating an "OrdersController" that implements ModelDriven. After implementing a setId() method (to set the id from the request parameters), a getModel() method (to return the Order object) and implementing a show() method that returns HttpHeaders, Don starts up his server and shows that http://localhost:8080/order/5 returns an HTML page. Changing the URL to end in /5.json returns JSON, /5.xml returns XML.

public HttpHeaders create() {
    service.save(order);
    return new DefaultHttpHeaders("success").setLocationId(order.getId());
}

The Poster Plugin for Firefox is great when you're working with REST services. Don used this plugin to show us that it's possible to post to JSON and get back JSON results. His demo was impressive, especially the fact that there was no XML configuration required for Struts. I also like how the DefaultHttpHeaders class allows you to manipulate headers in a type-safe manner.

To use the REST plugin, you'll want to use Struts 2.1. If you're using Maven, all you need to depend on is struts-rest-plugin. The struts-codebehind-plugin (as well as struts-core) will be pulled in by transitive dependencies.

One disadvantage of REST vs. WS-* is you can't generate client code from a WSDL. You'll have to write your client by hand. However, one advantage of REST is there's already lots of clients - your browser, curl, etc.

The Struts REST Plugin hasn't been officially released, but hopefully will be in Struts 2.1.1. You can checkout the code from SVN using the URL below. The documentation is located here.

http://svn.apache.org/repos/asf/struts/struts2/trunk/plugins/rest

Great talk Don - and excellent work on the REST plugin for Struts. I can't wait to try it out.

Comparing Web Frameworks: Time for a Change?

I first came up with the idea to do a "Comparing Web Frameworks" talk in 2004. I submitted a talk to ApacheCon and it got accepted. From there, I outlined, created sample apps and practiced this talk before ApacheCon. Believe it or not, that was my first time speaking in front of a large audience.

Historical note: October 2004 was a pretty cool month - I discovered Rails and Roller had a 1.0 release candidate.

When I created the presentation, it was in large part due to all the WebWork and Tapestry folks harassing me on this very blog. I started using Struts in June 2001 (the same month 1.0 was released) and had used it successfully on many projects. Part of the reason this blog became so popular was I posted lots of tips and tricks that I learned about Struts (and its related project) while using it. After a while, the noise became too heavy to ignore it - especially after I'd tried Spring MVC. So in an effort to learn more about the the other frameworks, I submitted a talk and forced myself to learn them. It seems to have worked out pretty well.

With that being said, I think it's time for a change. The reason I originally wrote this was to educate developers on how the top Java web frameworks differed and encourage developers to try more than one. A while later, I realized there's different tools for different jobs and it's not a one-size-fits-all web framework world. It's not a component vs. request-based framework world either. There's lots of options now. When I've delivered this talk earlier this year, I've always felt like I've left quite a few frameworks out. The solution could be to add more and more frameworks. However, I don't think that's a good idea. The talk is already difficult to squeeze into 90 minutes and it's unlikely that adding more frameworks is going to help.

The change I'd like to do is to reduce the number of frameworks down to (what I consider) the top web frameworks for deploying to the JVM. What are those frameworks? IMHO, they are as follows, in no particular order:

• GWT-Ext
• Wicket
• Grails
• Flex/OpenLaszlo
• Seam
• Struts 2

The RIFE, Tapestry and ZK folks can start bitching now. Sorry - less frameworks make for a more interesting talk. Maybe I'll add you in the future and I can ask the audience which ones they want compared then we can choose four and go from there. Why don't I mention Spring MVC? Because I think Struts 2 is easier to learn and be productive with and I also like it's more open and active community. I've written applications with both and I like Struts 2 better. As for Flex vs. OpenLaszlo, I'm somewhat torn. It seems like learning Flex is going to be better for your career, but it's likely useless without the Flex Builder - which is not open source. However, at $250, it's likely worth its price. I know the Picnik folks used Flex for their UI - I wonder how much they used Flex Builder in the process?

What do you think? Are these the top web frameworks for JVM deployment today? The next time I give this talk is this Thursday at ApacheCon. I may try to re-write my talk and then give the audience a choice of old vs. new. The downside of doing the new talk is I won't have time to write apps with GWT, Flex or Seam. Anyone care to post their top three pros and cons for any of these frameworks?

Upgrading AppFuse to Spring 2.5

Last night, I spent a few minutes upgrading AppFuse to Spring 2.5 RC1. According to InfoQ, Spring 2.5 is a drop-in upgrade for Spring 2.0. However, if you're using Maven, it's not quite that easy. The good news is it is easy, you just need to change your pom.xml a bit. The steps I used to upgrade AppFuse are listed below:

• Add a repository for Spring's milestone releases:

  <repository>
      <id>spring-milestone</id>
      <url>http://s3.amazonaws.com/maven.springframework.org/milestone</url>
  </repository>
  

• Change artifactId of "spring-mock" to be "spring-test".
• Change version to be 2.5-rc1.

At this point, if you're using "spring" as your artifactId (instead of the smaller fine-grained dependencies), you'll likely get the following error in a Spring MVC application:

java.lang.NoClassDefFoundError: 
org/springframework/web/servlet/handler/AbstractUrlHandlerMapping

This happens because Spring MVC is no longer included in the uber spring.jar. You'll need to add a dependency on "spring-webmvc" to solve this problem. Unfortunately, this JAR is dependent on the fine-grained modules, so you may have to modify your pom.xml to depend on the fine-grained modules - or exclude them all from spring-webmvc.

The good news is Spring has excluded all the invalid commons-logging dependencies for you so you don't have to anymore.

After getting all the dependencies straightened out - I ran the integration tests:

org.springframework.beans.NotReadablePropertyException: Invalid property 
'fileUpload' of bean class [org.appfuse.webapp.controller.FileUpload]: Bean 
property 'fileUpload' is not readable or has an invalid getter method: Does the 
return type of the getter match the parameter type of the setter?

Looking at uploadForm.jsp, I'm guessing the problem happens because of the following code:

<spring:bind path="fileUpload.file">
<input type="file" name="file" id="file" class="file medium" value="<c:out value="${status.value}"/>"/>
</spring:bind>

Confirmed - changing the "path" attribute to "file" fixes the problem. I also found out that setting the "value" on an <input type="file"> doesn't work, so wrapping the field with <spring:bind> doesn't make a whole lot of sense anyway.

To conclude, it doesn't look like the first release candidate of Spring 2.5 is exactly a drop-in upgrade for Spring 2.0, but it's pretty darn close. I'm sure by the time it's released, it will be. I'd encourage you to try 2.5 in your Spring-dependent projects to see if you find any issues.

Update: I was successfully able to migrate AppFuse from using the uber JAR to fine-grained JARs. However, I ran into a couple issues in the process. The first is that even though I'm including spring-aop in the appfuse-service module, it's not pulled in for the web frameworks (which depend on appfuse-service). Explicitly declaring spring-aop as a dependency for the appfuse-web module fixes this. Secondly, I had to modify my Acegi Security exclusions so it wouldn't include dependencies that no longer exist in 2.5.

<dependency>
    <groupId>org.acegisecurity</groupId>
    <artifactId>acegi-security-tiger</artifactId>
    <version>${acegi.version}</version>
    <exclusions>
        <exclusion>
            <groupId>org.springframework</groupId>
            <artifactId>spring-dao</artifactId>
        </exclusion>
        <exclusion>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
        </exclusion>
        <exclusion>
            <groupId>org.springframework</groupId>
            <artifactId>spring-remoting</artifactId>
        </exclusion>
        <exclusion>
            <groupId>org.springframework</groupId>
            <artifactId>spring-support</artifactId>
        </exclusion>
    </exclusions>
</dependency>

Flex and Grails Made Easy

I love how easy it is to start new projects these days. It was very difficult when I started creating AppFuse way back in 2002. We've come a long way baby!

Here's a couple of easy ways to get started with Flex and Grails:

• Quickstart flex development with this maven archetype
• Grails development in IntelliJ IDEA

I hope to develop with Flex, Grails, GWT or YUI + Struts 2 in the next 6 months. These seem like the most exciting technologies for Java web development in 2008.

Maven Meetup in San Francisco tomorrow (Tuesday)

If you live in the Bay Area and you're interested in talking with the inventors of Maven and/or XWiki, you should checkout the XWiki + Maven meetup at Terracotta's HQ. Java Open Source gurus Vincent Massol and Jason van Zyl will be there - sounds like a fun event!

GlassFish 2 vs. Tomcat 6

In Switched, Dave says:

Now that Glassfish V2 is out I'm switching from Tomcat to Glassfish for all of my development. It's more than fast enough. With Glassfish on my MacBook Pro, Roller restart time is about 8 seconds compared to 16 with Tomcat. And the quality is high; the admin console, the asadmin command-line utility and the docs are all excellent. The dog food is surprisingly tasty ;-)

I did some brief and very non-scientific performance comparisons myself:

Startup Time with no applications deployed:

• Tomcat 6: 3 seconds
• GlassFish 2: 8 seconds

Startup Time with AppFuse 2.0 (Struts + Hibernate version) as a WAR

• Tomcat 6: 15 seconds
• GlassFish 2: 16 seconds

Environment:

• JAVA_OPTS="-Xms768M -Xmx768M -XX:PermSize=512m -XX:MaxPermSize=512m -Djava.awt.headless=true -XX:+CMSClassUnloadingEnabled -XX:+CMSPermGenSweepingEnabled -XX:+UseConcMarkSweepGC -server"
• OS X 10.4.10, 2.2 GHz Intel Core 2 Duo, 4 GB 667 MHz DDR2 SDRAM

Since this was a very non-scientific experiment, it's possible the last two are actually the same. It's strange that Dave is seeing Roller startup twice as fast on GlassFish. Maybe they've done some Roller deployment optimization?

I realize startup times aren't that important. However, as Dave mentions, they (and context reloading) can be extremely important when developing.

Update: I got to thinking that Dave is probably referring to context reloading. Here's a comparison of how long it takes for both servers to pick up a new WAR (and start the application) when it's dropped into their autodeploy directories.

• Tomcat 6: 14-16 seconds
• GlassFish 2: 9 seconds

The strange thing about Tomcat is it takes 6-8 seconds to recognize a new WAR has been deployed. Does Tomcat have a polling increment that can be increased during development?

Regardless, it's impressive that the GlassFish guys have made things that much faster for developers. Nice work folks!

These days, I try to use mvn jetty:run on projects. Then I don't have to worry about deploying, just save and wait for the reload. Time to wait for AppFuse 2.0 to reload using the Maven Jetty Plugin (version 6.1.5)? 7 seconds. Of course, it'd be nice if I could somehow get this down to 1 or 2 seconds.

Maybe Dave should use the Maven integration for Roller to decrease his reload times. ;-)

AppFuse 2.0 Released!

I'm extremely happy to announce we've finally finished developing AppFuse 2.0. The road to AppFuse 2.0 has been a long journey through Mavenland, annotations and generics. Thanks to all the developers, contributors and users for helping test, polish and prove that AppFuse 2 is an excellent solution for developing Java-based applications. Your time, patience and usage of AppFuse has made it the strong foundation it is today. Last but certainly not least, thanks to all the great Java developers who wrote the frameworks that AppFuse uses - we're truly standing on the shoulders of giants.

What is AppFuse? Click here to find out.

AppFuse is an open source project and application that uses open source tools built on the Java platform to help you develop Web applications quickly and efficiently. It was originally developed to eliminate the ramp-up time found when building new web applications for customers. At its core, AppFuse is a project skeleton, similar to the one that's created by your IDE when you click through a wizard to create a new web project.

AppFuse 1.x uses Ant to create your project, as well as build/test/deploy it. AppFuse 2.0 uses Maven 2 to create your project as well as build/test/deploy it. IDE support is much better in 2.0 because you can generate the IDE project files with Maven plugins. AppFuse 1.x uses XDoclet and JDK 1.4+.

This project was started in April 2003.

AppFuse 2.0 is available as a Maven archetype. For information on creating a new project using this release, please see the QuickStart Guide or the demos and videos.

If you've used AppFuse 1.x, but not 2.x, you'll might want to read our Frequently Asked Questions. If you have any questions or issues, please post them to the user mailing list. The Maven Reference Guide has a map of Ant » Maven commands. Maven for Newbies might also be useful if you've never used Maven before. There is some support for Ant in this release.

AppFuse 2.0 contains over 200 pages of documentation, downloadable as a PDF (3 MB). You can also download all its dependencies and install them in your local repository if you want to work offline.

For more information, please see the 2.0 Release Notes. The 2.0 series of AppFuse has a minimum requirement of the following specification versions:

• Java Servlet 2.4 and JSP 2.0 (2.1 for JSF)
• Java 5+

New features in AppFuse 2.0 include:

• Maven 2 Integration
• Upgraded WebWork to Struts 2
• JDK 5, Annotations, JSP 2.0, Servlet 2.4
• JPA Support
• Generic CRUD backend
• Full Eclipse, IDEA and NetBeans support
• Fast startup and no deploy with Maven Jetty Plugin
• Testable on multiple appservers and databases with Cargo and profiles

We appreciate the time and effort everyone has put toward contributing code and documentation, posting to the mailing lists, and logging issues.

We're also grateful for the help from our sponsors, particularly Atlassian, Contegix, JetBrains, and Java.net. Atlassian and Contegix are especially awesome: Atlassian has donated licenses to all its products and Contegix has donated an entire server to the AppFuse project. Thanks guys - you rock!

Comments and issues should be posted to the mailing list.