Raible Designs

Friday May 16, 2008

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. Posted in Java at May 16 2008, 06:17:52 PM MDT 3 Comments

Sunday May 11, 2008

AppFuse 2.0.2 Released The AppFuse Team is pleased to announce the release of AppFuse 2.0.2. This release includes upgrades to Spring Security 2.0, jMock 2.4, the ability to customize code generation templates and many bug fixes.

For information on upgrading from 2.0.1, see the Release Notes or changelog. AppFuse 2.0.2 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.

To learn more about AppFuse, please read Ryan Withers' Igniting your applications with AppFuse.

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.

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

Posted in Java at May 11 2008, 11:25:40 PM MDT 3 Comments

Wednesday April 30, 2008

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. Posted in Java at Apr 30 2008, 12:42:34 AM MDT 9 Comments

Monday April 07, 2008

Spring MVC's Conventions get even better Spring 2.5.3 was released this morning and contains a new feature I really like. When I first started working with Spring MVC's annotations (way back in November of last year), I found it awkward that I had to hard-code the URLs for my controllers into @RequestMappings on methods. Previous to annotations, I was using Spring's ControllerClassNameHandlerMapping which allows for more conventions-based URL-mappings.

With 2.5.3, @Controller and ControllerClassNameHandlerMapping have been synced up so you don't have to specify URLs in your annotations anymore. Thanks guys! Posted in Java at Apr 07 2008, 09:43:42 AM MDT 4 Comments

Friday February 22, 2008

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. Posted in Java at Feb 22 2008, 02:47:44 PM MST 6 Comments

Thursday December 06, 2007

Spring Security 2 It looks like we'll have to wait until next week to get our hands on Spring Security 2 (the next release of Acegi Security). The good news is it looks much simpler. From what I can tell, this new code is available in Acegi's SVN repository. Here's to hoping the Acegi Team writes some sort of migration guide. Posted in Java at Dec 06 2007, 03:52:34 PM MST 3 Comments

Wednesday December 05, 2007

Spring MVC, JstlView and exposeContextBeansAsAttributes Did you know that Spring MVC's JstlView has a exposeContextBeansAsAttributes property you can use to expose all your Spring beans to JSTL? I didn't. To configure it, you configure your viewResolver as follows:

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

After doing this, any Spring bean can get referenced in JSTL with:

${beanId.getterMethodWithoutTheGetPrefix}

If you're using Spring 2.5a annotations and <context:component-scan>, you'll need to specify a "value" attribute on your annotations in order to reference them in JSTL. For example:

@Controller(value = "beanId")
@RequestMapping("/foo.html")
public class MyController extends SimpleFormController

...

@Component(value="testClass")
public class TestClass {

Pretty cool stuff. It'd be a lot more useful if you could call methods with parameters. Hopefully JUEL will solve that problem. JSTL's functions work, but I'd rather write ${foo.method('arg')} rather than ${taglib:callMethod(foo, 'method', 'arg')}. Posted in Java at Dec 05 2007, 06:34:41 PM MST 5 Comments

Monday November 26, 2007

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.

Posted in Java at Nov 26 2007, 09:29:43 AM MST 4 Comments

Wednesday November 07, 2007

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>

Posted in Java at Nov 07 2007, 08:27:20 AM MST 3 Comments

Tuesday October 23, 2007

Google Goods at the Colorado Software Summit This morning, I woke up early and attended Dion Almaer's talk on Google Gears. Dion works at Google in the Developer API group and is a member of the Google Gears development team. This presentation is called How to take your Web Application offline with Google Gears.

Dion starts with a video that Google Developers made. It's a parody of Dick in a Box, but it's called API in a Box. This was by far my favorite part of the presentation and it all went downhill from there.

Gears is a browser plugin that adds a database and a JavaScript API that allows applications to "go offline" and use these resources to store data. It does not do anything to handle synchronization of data back to the online database.

Gears has three modules as part of its API: LocalServer, Database and Workerpool.

The Database is embedded using SQLite. Google contributed Full Text Search to it and the entire database is 250K. Below is an example of how you might use the API:

var db = google.gears.factory.create("beta.database", "1.0");
db.open("database-demo");
db.execute("create table if not exists ...");
...
var rs = db.execute("select * from Demo order by Timestamp desc");
while (rs.isValidRolw()) {
    var name = fs.field(|);
    ...
}

During the rest of the talk, I tuned in and out, but caught a number of interesting tidbits:

• GearShift - DB Migrations for Gears.
• Database Query Tool - one-page browser-based application that can be added to existing applications to add a query browser.
• Gears in Motion - full database tool for creating databases, modifying tables, inline-editing, etc. After building your database, you can export the SQL for use in a Gears application.
• Syncing is not a part of Gears because it's a very difficult problem to solve - especially when you have huge data.
• The best way to implement synching is to start simple, like Zoho Writer. It's like Google Docs, but allows you to read your documents off-line. The next version they're planning on allowing offline editing.
• You should plan on allowing your application to run - possibly by using cookies to store the data and create a "CookieBaseContent" implementation that gets chosen instead of "GearsBaseContent". In other words:

  content = hasGears() ? new GearsBaseContent() : new CookieBaseContent();
  

• Debugging is a pain - you can simplify by using helper functions that allow you to clear the database.
• Google's Read/Write JavaScript API looks like some really cool stuff. It solves the cross-domain problem and is (at its core) a clever bundling of browser hacks. It's not specific to Google's APIs and can be used in any Ajax application.
• Gearsmonkey - uses Google Gears with the Firefox Greasemonkey plug-in to take other's applications offline.
• Dion uses Greasemonkey to add keystrokes to GMail and remove ads from Facebook.
• Wikipedia has an offline version that's powered by Gears. It uses iframes to cache pages with Gears and was developed by Google. It's unannounced by Dion didn't say I couldn't blog about it.
• Dojo offline has a sync framework.
• Vortex is an offline toolkit that builds on Gears.
• GWT has Gears support - all you have to do is drop a JAR in your classpath. If you don't like using Gear's JDBC-esque API - maybe you can use Hibernate with Gears?

Dion ended by talking about how Adobe Air is great for desktop-like applications that you can easily build with Ajax technologies. Silverlight is impressive, but only for media applications - you have to draw components yourself. Java Applets may make a comeback. The browser plugin has been rewritten to be fast as well as have full support for Java Web Start. It's possible that Gears + the Java Plugin can make it possible to use Java technologies (i.e. Hibernate or JPA) to talk to the browser's database. Firefox and WebKit are adding database components to their next major releases - so offline applications should become even easier to develop in the future.

Overall, this was a great talk - largely because Dion is a great speaker and made it fun and interesting.

After Dion's talk, I delivered my Web Framework talk and had some lunch while trying to get Rockies tickets (no luck). After lunch, I attended Bill Dudney's Comparing Spring & Guice talk. I learned some things about Guice I didn't know and enjoyed his comparison of the two Dependency Injection frameworks.

One question that Bill couldn't answer is how Spring 2.5's annotation support stacks up against Guice. Is it as full-featured as Guice? Does it add additional features and keep up with Guice for performance? What about wiring up objects without annotations - does it allow you to autowire your classes based on naming patterns without annotations in your code? What I'm hoping for is a DI framework that allows me to autowire classes using rules/conventions rather than annotations. I'm fine with using annotations for edge-cases, but it seems like a lot of the DI I do these days could be configured up-front and used for the entire application (rather than having to wire up each class).

Overall, it was a great day at the Colorado Software Summit.

Posted in Java at Oct 23 2007, 05:46:56 PM MDT 4 Comments