Raible Designs

What's a good RIA to develop in 20 hours?

In less than two months, I'm making my annual trek to Portland, Oregon to speak at OSCON. To prepare for my talk, I'd like to develop the same application with two different combinations: Flex + Rails and GWT + Grails.

As luck would have it, I'm having a hard time coming up with a good application to write. I'd like to time-box it so I only spend 10 hours on the backend (for each) and 10 hours on the front-end, for a total of 40 hours for both applications.

Can you think of any good applications that would warrant a rich front-end and wouldn't take too long to create? I'd like to put both applications in production and generate enough traffic to be faced with scalability issues.

Over the next several weeks, I hope to start creating the applications and blog about what I've learned along the way. At some point, I hope to post an outline and a rough draft. With your help, I believe this can be an excellent presentation. If the presentation and applications are as good as I hope they'll be, it's likely I'll open source them for everyone to use.

Thanks in advance for any advice.

Update: Thanks for all the great feedback. I've posted a survey to narrow the choices.

New Mac Pro

It sure is cool when dreams come true. Look what arrived at the Denver office today.

Update: Believe it or not, I rebooted my MacBook Pro the same minute I plugged in my Mac Pro. Upon reboot, the MBP choked and I've been looking at a gray screen with a spinning icon for most of the day. I'm soooo glad I have Time Machine. Let's hope I can do a restore on the MBP tomorrow.

Update 2: I was able to successfully build the Mac Pro from my latest MacBook Pro backup on Time Machine. Sweet! Let's see how this works:

$ echo $JAVA_OPTS
-Xms512M -Xmx4096M -XX:PermSize=384m -XX:MaxPermSize=512m -Djava.awt.headless=true -XX:+CMSClassUnloadingEnabled -XX:+CMSPermGenSweepingEnabled -XX:+UseConcMarkSweepGC -server

2008: The Year of Beer

In a few weeks, I'm heading to the American Craft Beer Festival in Boston. In July, I'll be attending the Oregon Brewers Festival in Portland (followed by a night at McMenamins Kennedy School). A friend and I just booked flights for Oktoberfest in Munich. A couple weeks after Oktoberfest, I'll be attending the Great American Beer Festival in Denver.

Homer would be proud.

Why no more than 500 connections?

I recently updated my status on LinkedIn to read:

Matt is determined not to have 500+ connections. Will start removing connections soon.

A couple of days later, I received the following message from a connection:

I noticed the other day you mentioned that you are determined to not have over 500 LinkedIn connections. I'm wondering what the reason is? Not just because LinkedIn shows 500+ after that, is it? As you work for LinkedIn, I assume there's some other reason. I'm interested to know what it is...

I joined LinkedIn May 27, 2003, 22 days after it initially launched. For the first few years, I accepted invitations when I received them. Some folks I knew, some I didn't. When I started consulting for LinkedIn last summer, I had somewhere between 200 and 300 connections. Most of them were people who had contacted me, not folks I had contacted.

One day, I used the import webmail contacts feature to pull in my contacts from Gmail. My number of connections quickly jumped by 100 and it's increased quite a bit since then (mostly due to co-workers from LinkedIn). Of the almost 500 connections I have, I believe there's a good 100-200 of them that are folks I don't know, have never had contact with, and will likely never benefit from being "connected" with.

I guess the main reason I'm planning on trimming my connections is to make my network higher quality. I admit I'm somewhat motivated by the 500+ icon, but it's also a genuine feeling that there's quite a few folks I won't benefit from being connected to. I'm not a LION after all. I believe my LinkedIn network should resemble my real-world network.

What's your opinion? Should I have folks in my network that know me, but I don't know them?

Should we change AppFuse to be Struts 2-specific?

Dusty recently posted an interesting idea to the AppFuse developers mailing list:

After thinking/coding/reading for a while I think the more interesting task is: Retool AppFuse to be one or more Struts2 plugins based on various higher level app patterns. (AppFuse Facebook, AppFuse Employee DB, AppFuse Blog, AppFuse Basic LDAP, AppFuse Basic Crowd).

This all comes from the fact, that I have been wanting to refactor the AppFuse web layer for Struts. One of the interesting aspects of AppFuse is that it works pretty much the same across all its web frameworks. It does so with some lowest common denominator abstractions that can be ported and look and work the same across frameworks. I have picked my tool(s): Struts 2 and Ruby On Rails when I want to pretend I am young again. I know Spring MVC, JSF, etc. but I have no desire to build significant apps on those platforms. It's not because they suck and Struts2 rules, it is because I know Struts 2 the best, I am most efficient there and it provides everything I need to build great webapps (Let's not devolve to a framework debate). So, I would rather have a more Struts 2-specific web stack, that really leverages conventions born and raised there. The nice thing about the Struts 2 web stack is that it is complemented nicely by AppFuse's data/service layer, since unlike Grails or Rails, Struts 2 has no data or service layer. [Read More »]

Seems like a good idea to me. What do you think?

Someday I'd like to come up with a "compatibility test" that allows others to improve upon the ideas in AppFuse and develop their stacks independently. A suite of Selenium tests that require extensionless URLs might be a good start.

AppFuse + DisplayTag: External Sorting and Paging Example

Chris Barham has posted an excellent example of how to do external sorting and paging to the AppFuse mailing list:

I've put together a new AppFuse project which demonstrates how to enhance the List screens. DisplayTag as provided has issues with large datasets, (it retrieves all the records every time), and sorting via column headings does not work for the entire dataset, only those on screen at the time.

I've built a project which addresses these issues, using Hibernate Criteria and extensions to DisplayTags PaginatedList interface which gets DisplayTag to hand off all requests for sorting and paging to the new implementation of PaginatedList.

The Google Code project is checked in to: http://code.google.com/p/pagingappfuse/ feel free to check out the code and comment. (instructions here: http://code.google.com/p/pagingappfuse/source/checkout)

There are instructions regarding the steps taken on the project wiki page here: http://code.google.com/p/pagingappfuse/wiki/PagingSorting

Cheers,
Chris

Nice work - thanks Chris!

Spring MVC vs. JSF and The State of Spring Web

Alternative Adult has only posted a couple times in 2008, but his entries have peaked my interest.

Spring MVC or JSF+?
My business unit is trying to standardize if we can on a single Java-based Web framework going forward to simplify the Web development process, especially as individual developers move from one division to another, or centralized support groups need to maintain multiple applications from multiple divisions.

At the enterprise level within my company, the architecture group says that they will provide support for either Spring MVC or JSF+ (where the + represents the accompanying technologies you would use to provide a more maintainable application and a more rich user experience, e.g. Facelets, Richfaces, etc.).

Now my business unit is trying to decide which of these two frameworks, Spring MVC or JSF+, is the most appropriate to standardize upon for our development community. [Read More]

...and...

State of Spring Web
For those that are interested, the following is a summary of the notes I captured from a conversation with SpringSource on the state of Spring Web. [Read More]

Good stuff Michael - keep it coming.

Extensionless URLs with Java Web Frameworks

Last week, I had a go of making a Spring MVC application use extensionless URLs. I did some googling, found some tips on the Spring Forums and believe I arrived at a solid solution. Using the UrlRewriteFilter (version 3), I was able to create a rule that looks for any URLs without an extension. If it finds one, it appends the extension and forwards to the controllers. This rule is as follows (where *.html is my servlet-mapping for DispatcherServlet in web.xml):

  <rule>
    <from>^([^?]*)/([^?/\.]+)(\?.*)?$</from>
    <to last="true">$1/$2.html$3</to>
  </rule>

As long as I hand-write all my URLs without an extension (<a href="home"> vs. <a href="home.html">), this seems to work. To combat developers that use "home.html", one solution is to require all links to be wrapped with <c:url value="url"/> (or some other macro that call response.encodeURL()). If you can convince everyone to do this, you can write an outbound-rule that strips the .html extension from URLs.

  <outbound-rule>
    <from>^(.*)\.html(\?.*)?$</from>
    <to last="false">$1$2</to>
  </outbound-rule>

In an ideal world, it'd be possible to modify the <a> tag at the very core of the view framework you're using to automatically encode the URL of any "href" attributes. I don't think this is possible with JSP, FreeMarker, Facelets or any other Java Web Framework templates (i.e. Tapestry or Wicket). If it is, please let me know.

Below is my final urlrewrite.xml with these rules, as well as my "welcome-file" rule at the top.

<?xml version="1.0" encoding="utf-8"?>
<!DOCENGINE urlrewrite PUBLIC "-//tuckey.org//DTD UrlRewrite 3.0//EN"
  "http://tuckey.org/res/dtds/urlrewrite3.0.dtd">

<urlrewrite>
  <rule>
    <from>/$</from>
    <to type="forward">home</to>
  </rule>

  <rule>
    <from>^([^?]*)/([^?/\.]+)(\?.*)?$</from>
    <to last="true">$1/$2.html$3</to>
  </rule>

  <outbound-rule>
    <from>^(.*)\.html(\?.*)?$</from>
    <to last="false">$1$2</to>
  </outbound-rule>

</urlrewrite>

If you have other solutions for extensionless URLs with Java web frameworks, I'd love to hear about them. With any luck, 2008 will be the year we drop extensions (and path-mappings) from our URLs. The stat packages might not like it, but I do.

JavaOne Parties Update

In an effort to keep one of the top spots for "javaone parties", here's the updated list for JavaOne parties this week:

• Tuesday: CodeGear: Thirsty Bear @ 5:30, Open Source UnBOF: Thirsty Bear @ 8, TangoSolarMetric: Zebulon @ 9
• Wednesday: Adobe: Jillian's @ 6:30, Eclipse: Thirsty Bear @ 7, Tiki Bar Party: The Bamboo Hut @ 8
• Thursday: JBoss: Jillian's @ 5:30, QCon: Zebulon @ 6:30

Thanks to Atlassian for the free beer last night at Thirsty Bear. I'll likely be at Thirsty Bear tonight, followed by Zebulon. Let the networking begin!

Related: JavaOne: Where are the good parties at?

Running Spring MVC Web Applications in OSGi

For the past couple of weeks, I've been developing a web application that deploys into an OSGi container (Equinox) and uses Spring DM's Spring MVC support. The first thing I discovered was that Spring MVC's annotations weren't supported in the M1 release. This was apparently caused by a bug in Spring 2.5.3 and not Spring DM. Since Spring DM 1.1.0 M2 was released with Spring 2.5.4 today, I believe this is fixed now.

The story below is about my experience getting a Spring MVC application up and running in Equinox 3.2.2, Jetty 6.1.9 and Spring DM 1.1.0 M2 SNAPSHOT (from last week). If you want to read more about why Spring MVC + OSGi is cool, see Costin Leau's Web Applications and OSGi article.

To get a simple "Hello World" Spring MVC application working in OSGi is pretty easy. The hard part is setting up a container with all the Spring and Jetty bundles installed and started. I imagine SSAP might solve this. Luckily for me, this was done by another member of my team.

After you've done this, it's simply a matter of creating a MANIFEST.MF for your WAR that contains the proper information for OSGi to recognize. Below is the one that I used when I first tried to get my application working.

Manifest-Version: 1
Bundle-ManifestVersion: 2
Spring-DM-Version: 1.1.0-m2-SNAPSHOT
Spring-Version: 2.5.2
Bundle-Name: Simple OSGi War
Bundle-SymbolicName: myapp
Bundle-Classpath: .,WEB-INF/classes,WEB-INF/lib/freemarker-2.3.12.jar,
 WEB-INF/lib/sitemesh-2.3.jar,WEB-INF/lib/urlrewritefilter-3.0.4.jar,
 WEB-INF/lib/spring-beans-2.5.2.jar,WEB-INF/lib/spring-context-2.5.2.jar,
 WEB-INF/lib/spring-context-support-2.5.2.jar,WEB-INF/lib/spring-core-2.5.2.jar,
 WEB-INF/lib/spring-web-2.5.2.jar,WEB-INF/lib/spring-webmvc-2.5.2.jar 
Import-Package: javax.servlet,javax.servlet.http,javax.servlet.resources,javax.swing.tree,
 javax.naming,org.w3c.dom,org.apache.commons.logging,javax.xml.parsers;resolution:=optional,
 org.xml.sax;resolution:=optional,org.xml.sax.helpers;resolution:=optional

Ideally, you could generate this MANIFEST.MF using the maven-bundle-plugin. However, it doesn't support WARs in its 1.4.0 release.

You can see this is an application that uses Spring MVC, FreeMarker, SiteMesh and the URLRewriteFilter. You should be able to download it, unzip it, run "mvn package" and install it into Equinox using "install file://<path to war>".

That's all fine and dandy, but doesn't give you any benefits of OSGi. This setup works great until you try to import OSGi services using a context file with an <osgi:reference> element. After adding such a reference, it's likely you'll get the following error:

SEVERE: Context initialization failed
org.springframework.beans.factory.parsing.BeanDefinitionParsingException:
Configuration problem: Unable to locate Spring NamespaceHandler for
XML schema namespace [http://www.springframework.org/schema/osgi]

To fix this, add the following to your web.xml (if you're using ContextLoaderListener, as an <init-parameter> on DispatcherServlet if you're not):

  <context-param>
    <param-name>contextClass</param-name>
    <param-value>org.springframework.osgi.web.context.support.OsgiBundleXmlWebApplicationContext</param-value>
  </context-param>

After doing this, you might get the following error on startup:

SEVERE: Context initialization failed
org.springframework.context.ApplicationContextException: Custom
context class [org.springframework.osgi.web.context.support.OsgiBundleXmlWebApplicationContext]
is not of type [org.springframework.web.context.ConfigurableWebApplicationContext] 

To fix this, I change from referencing the Spring JARs in WEB-INF/lib to importing the packages for Spring (which were already installed in my Equinox container).

Bundle-Classpath: .,WEB-INF/classes,WEB-INF/lib/freemarker-2.3.12.jar,
 WEB-INF/lib/sitemesh-2.3.jar,WEB-INF/lib/urlrewritefilter-3.0.4.jar
Import-Package:
javax.servlet,javax.servlet.http,javax.servlet.resources,javax.swing.tree,
 javax.naming,org.w3c.dom,org.apache.commons.logging,javax.xml.parsers;resolution:=optional,
 org.xml.sax;resolution:=optional,org.xml.sax.helpers;resolution:=optional,
 org.springframework.osgi.web.context.support,
 org.springframework.context.support,
 org.springframework.web.context,
 org.springframework.web.context.support,
 org.springframework.web.servlet,
 org.springframework.web.servlet.mvc,
 org.springframework.web.servlet.mvc.support,
 org.springframework.web.servlet.view,
 org.springframework.ui,
 org.springframework.web.servlet.view.freemarker 

After rebuilding my WAR and reloading the bundle in Equinox, I was confronted with the following error message:

SEVERE: Context initialization failed
org.springframework.beans.factory.BeanCreationException: Error
creating bean with name 'freemarkerConfig' defined in ServletContext
resource [/WEB-INF/myapp-servlet.xml]: Instantiation of bean failed;
nested exception is java.lang.NoClassDefFoundError:
freemarker/cache/TemplateLoader
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:851) 

As far as I can tell, this is because the version of Spring MVC installed in Equinox cannot resolve the FreeMarker JAR in my WEB-INF/lib directory.

To prove I wasn't going insane, I commented out my "freemarkerConfig" and "viewResolver" beans in myapp-servlet.xml and changed to a regular ol' InternalResourceViewResolver:

<bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
    <property name="prefix" value="/"/>
    <property name="suffix" value=".jsp"/>
</bean>

This worked and I was able to successfully see "Hello World" from a JSP in my browser. FreeMarker/SiteMesh worked too, but FreeMarker didn't work as a View for Spring MVC.

To attempt to solve this, I create a bundle for FreeMarker using "java -jar bnd-0.0.249.jar wrap freemarker-2.3.12.jar" and installed it in Equinox. I then change my MANIFEST.MF to use FreeMarker imports instead of referencing the JAR in WEB-INF/lib.

Bundle-Classpath:
.,WEB-INF/classes,WEB-INF/lib/sitemesh-2.3.jar,WEB-INF/lib/urlrewritefilter-3.0.4.jar
Import-Package:
javax.servlet,javax.servlet.http,javax.servlet.resources,javax.swing.tree,
 javax.naming,org.w3c.dom,org.apache.commons.logging,javax.xml.parsers;resolution:=optional,
 org.xml.sax;resolution:=optional,org.xml.sax.helpers;resolution:=optional,
 org.springframework.osgi.web.context.support,
 org.springframework.context.support,
 org.springframework.web.context,
 org.springframework.web.context.support,
 org.springframework.web.servlet,
 org.springframework.web.servlet.mvc,
 org.springframework.web.servlet.mvc.support,
 org.springframework.web.servlet.view,
 org.springframework.ui,
 org.springframework.web.servlet.view.freemarker,
 freemarker.cache,freemarker.core,freemarker.template,freemarker.ext.servlet 

Unfortunately, this still doesn't work and I still haven't been able to get FreeMarker to work with Spring MVC in OSGi. The crazy thing is I actually solved this at one point a week ago. Shortly after, I rebuilt Equinox from scratch and I'm been banging my head against the wall over this issue ever since. Last week, I entered an issue in Spring's JIRA, but thought I'd fixed it a few hours later.

I've uploaded the final project that's not working to the following URL:

http://static.raibledesigns.com/downloads/myapp-osgi.zip

If you'd like to see this project work with Spring MVC + JSP, simply modify myapp-servlet.xml to remove the FreeMarker references and use the InternalResourceViewResolver instead.

I hope Spring DM + Spring MVC supports more than just JSP as a view technology. I hope I can't get FreeMarker working because of some oversight on my part. If you have a Spring DM + Spring MVC application working with Velocity or FreeMarker, I'd love to hear about it.